Merge pull request #13049 from MrMino/empty_histrange_means_all

Accept empty history ranges

docs/source/whatsnew/pr/empty-hist-range.rst

@@ -0,0 +1,19 b''
+Empty History Ranges
+====================
+
+A number of magics that take history ranges can now be used with an empty
+range. These magics are:
+
+ * ``%save``
+ * ``%load``
+ * ``%pastebin``
+ * ``%pycat``
+
+Using them this way will make them take the history of the current session up
+to the point of the magic call (such that the magic itself will not be
+included).
+
+Therefore it is now possible to save the whole history to a file using simple
+``%save <filename>``, load and edit it using ``%load`` (makes for a nice usage
+when followed with :kbd:`F2`), send it to dpaste.org using ``%pastebin``, or
+view the whole thing syntax-highlighted with a single ``%pycat``.

IPython/core/history.py

@@ -1,897 +1,907 b''
 """ History related magics and functionality """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 
 import atexit
 import datetime
 from pathlib import Path
 import re
 import sqlite3
 import threading
 
 from traitlets.config.configurable import LoggingConfigurable
 from decorator import decorator
 from IPython.utils.decorators import undoc
 from IPython.paths import locate_profile
 from traitlets import (
     Any,
     Bool,
     Dict,
     Instance,
     Integer,
     List,
     Unicode,
     Union,
     TraitError,
     default,
     observe,
 )
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 @undoc
 class DummyDB(object):
     """Dummy DB that will act as a black hole for history.
 
     Only used in the absence of sqlite"""
     def execute(*args, **kwargs):
         return []
 
     def commit(self, *args, **kwargs):
         pass
 
     def __enter__(self, *args, **kwargs):
         pass
 
     def __exit__(self, *args, **kwargs):
         pass
 
 
 @decorator
 def only_when_enabled(f, self, *a, **kw):
     """Decorator: return an empty list in the absence of sqlite."""
     if not self.enabled:
         return []
     else:
         return f(self, *a, **kw)
 
 
 # use 16kB as threshold for whether a corrupt history db should be saved
 # that should be at least 100 entries or so
 _SAVE_DB_SIZE = 16384
 
 @decorator
 def catch_corrupt_db(f, self, *a, **kw):
     """A decorator which wraps HistoryAccessor method calls to catch errors from
     a corrupt SQLite database, move the old database out of the way, and create
     a new one.
 
     We avoid clobbering larger databases because this may be triggered due to filesystem issues,
     not just a corrupt file.
     """
     try:
         return f(self, *a, **kw)
     except (sqlite3.DatabaseError, sqlite3.OperationalError) as e:
         self._corrupt_db_counter += 1
         self.log.error("Failed to open SQLite history %s (%s).", self.hist_file, e)
         if self.hist_file != ':memory:':
             if self._corrupt_db_counter > self._corrupt_db_limit:
                 self.hist_file = ':memory:'
                 self.log.error("Failed to load history too many times, history will not be saved.")
             elif self.hist_file.is_file():
                 # move the file out of the way
                 base = str(self.hist_file.parent / self.hist_file.stem)
                 ext = self.hist_file.suffix
                 size = self.hist_file.stat().st_size
                 if size >= _SAVE_DB_SIZE:
                     # if there's significant content, avoid clobbering
                     now = datetime.datetime.now().isoformat().replace(':', '.')
                     newpath = base + '-corrupt-' + now + ext
                     # don't clobber previous corrupt backups
                     for i in range(100):
                         if not Path(newpath).exists():
                             break
                         else:
                             newpath = base + '-corrupt-' + now + (u'-%i' % i) + ext
                 else:
                     # not much content, possibly empty; don't worry about clobbering
                     # maybe we should just delete it?
                     newpath = base + '-corrupt' + ext
                 self.hist_file.rename(newpath)
                 self.log.error("History file was moved to %s and a new file created.", newpath)
             self.init_db()
             return []
         else:
             # Failed with :memory:, something serious is wrong
             raise
 
 
 class HistoryAccessorBase(LoggingConfigurable):
     """An abstract class for History Accessors """
 
     def get_tail(self, n=10, raw=True, output=False, include_latest=False):
         raise NotImplementedError
 
     def search(self, pattern="*", raw=True, search_raw=True,
                output=False, n=None, unique=False):
         raise NotImplementedError
 
     def get_range(self, session, start=1, stop=None, raw=True,output=False):
         raise NotImplementedError
 
     def get_range_by_str(self, rangestr, raw=True, output=False):
         raise NotImplementedError
 
 
 class HistoryAccessor(HistoryAccessorBase):
     """Access the history database without adding to it.
 
     This is intended for use by standalone history tools. IPython shells use
     HistoryManager, below, which is a subclass of this."""
 
     # counter for init_db retries, so we don't keep trying over and over
     _corrupt_db_counter = 0
      # after two failures, fallback on :memory:
     _corrupt_db_limit = 2
 
     # String holding the path to the history file
     hist_file = Union(
         [Instance(Path), Unicode()],
         help="""Path to file to use for SQLite history database.
 
         By default, IPython will put the history database in the IPython
         profile directory.  If you would rather share one history among
         profiles, you can set this value in each, so that they are consistent.
 
         Due to an issue with fcntl, SQLite is known to misbehave on some NFS
         mounts.  If you see IPython hanging, try setting this to something on a
         local disk, e.g::
 
             ipython --HistoryManager.hist_file=/tmp/ipython_hist.sqlite
 
         you can also use the specific value `:memory:` (including the colon
         at both end but not the back ticks), to avoid creating an history file.
 
         """,
     ).tag(config=True)
 
     enabled = Bool(True,
         help="""enable the SQLite history
 
         set enabled=False to disable the SQLite history,
         in which case there will be no stored history, no SQLite connection,
         and no background saving thread.  This may be necessary in some
         threaded environments where IPython is embedded.
         """
     ).tag(config=True)
 
     connection_options = Dict(
         help="""Options for configuring the SQLite connection
 
         These options are passed as keyword args to sqlite3.connect
         when establishing database connections.
         """
     ).tag(config=True)
 
     # The SQLite database
     db = Any()
     @observe('db')
     def _db_changed(self, change):
         """validate the db, since it can be an Instance of two different types"""
         new = change['new']
         connection_types = (DummyDB, sqlite3.Connection)
         if not isinstance(new, connection_types):
             msg = "%s.db must be sqlite3 Connection or DummyDB, not %r" % \
                     (self.__class__.__name__, new)
             raise TraitError(msg)
 
     def __init__(self, profile="default", hist_file="", **traits):
         """Create a new history accessor.
 
         Parameters
         ----------
         profile : str
           The name of the profile from which to open history.
         hist_file : str
           Path to an SQLite history database stored by IPython. If specified,
           hist_file overrides profile.
         config : :class:`~traitlets.config.loader.Config`
           Config object. hist_file can also be set through this.
         """
         # We need a pointer back to the shell for various tasks.
         super(HistoryAccessor, self).__init__(**traits)
         # defer setting hist_file from kwarg until after init,
         # otherwise the default kwarg value would clobber any value
         # set by config
         if hist_file:
             self.hist_file = hist_file
 
         try:
             self.hist_file
         except TraitError:
             # No one has set the hist_file, yet.
             self.hist_file = self._get_hist_file_name(profile)
 
         self.init_db()
 
     def _get_hist_file_name(self, profile='default'):
         """Find the history file for the given profile name.
 
         This is overridden by the HistoryManager subclass, to use the shell's
         active profile.
 
         Parameters
         ----------
         profile : str
           The name of a profile which has a history file.
         """
         return Path(locate_profile(profile)) / "history.sqlite"
 
     @catch_corrupt_db
     def init_db(self):
         """Connect to the database, and create tables if necessary."""
         if not self.enabled:
             self.db = DummyDB()
             return
 
         # use detect_types so that timestamps return datetime objects
         kwargs = dict(detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES)
         kwargs.update(self.connection_options)
         self.db = sqlite3.connect(str(self.hist_file), **kwargs)
         self.db.execute("""CREATE TABLE IF NOT EXISTS sessions (session integer
                         primary key autoincrement, start timestamp,
                         end timestamp, num_cmds integer, remark text)""")
         self.db.execute("""CREATE TABLE IF NOT EXISTS history
                 (session integer, line integer, source text, source_raw text,
                 PRIMARY KEY (session, line))""")
         # Output history is optional, but ensure the table's there so it can be
         # enabled later.
         self.db.execute("""CREATE TABLE IF NOT EXISTS output_history
                         (session integer, line integer, output text,
                         PRIMARY KEY (session, line))""")
         self.db.commit()
         # success! reset corrupt db count
         self._corrupt_db_counter = 0
 
     def writeout_cache(self):
         """Overridden by HistoryManager to dump the cache before certain
         database lookups."""
         pass
 
     ## -------------------------------
     ## Methods for retrieving history:
     ## -------------------------------
     def _run_sql(self, sql, params, raw=True, output=False):
         """Prepares and runs an SQL query for the history database.
 
         Parameters
         ----------
         sql : str
           Any filtering expressions to go after SELECT ... FROM ...
         params : tuple
           Parameters passed to the SQL query (to replace "?")
         raw, output : bool
           See :meth:`get_range`
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         toget = 'source_raw' if raw else 'source'
         sqlfrom = "history"
         if output:
             sqlfrom = "history LEFT JOIN output_history USING (session, line)"
             toget = "history.%s, output_history.output" % toget
         cur = self.db.execute("SELECT session, line, %s FROM %s " %\
                                 (toget, sqlfrom) + sql, params)
         if output:    # Regroup into 3-tuples, and parse JSON
             return ((ses, lin, (inp, out)) for ses, lin, inp, out in cur)
         return cur
 
     @only_when_enabled
     @catch_corrupt_db
     def get_session_info(self, session):
         """Get info about a session.
 
         Parameters
         ----------
 
         session : int
             Session number to retrieve.
 
         Returns
         -------
 
         session_id : int
            Session ID number
         start : datetime
            Timestamp for the start of the session.
         end : datetime
            Timestamp for the end of the session, or None if IPython crashed.
         num_cmds : int
            Number of commands run, or None if IPython crashed.
         remark : unicode
            A manually set description.
         """
         query = "SELECT * from sessions where session == ?"
         return self.db.execute(query, (session,)).fetchone()
 
     @catch_corrupt_db
     def get_last_session_id(self):
         """Get the last session ID currently in the database.
 
         Within IPython, this should be the same as the value stored in
         :attr:`HistoryManager.session_number`.
         """
         for record in self.get_tail(n=1, include_latest=True):
             return record[0]
 
     @catch_corrupt_db
     def get_tail(self, n=10, raw=True, output=False, include_latest=False):
         """Get the last n lines from the history database.
 
         Parameters
         ----------
         n : int
           The number of lines to get
         raw, output : bool
           See :meth:`get_range`
         include_latest : bool
           If False (default), n+1 lines are fetched, and the latest one
           is discarded. This is intended to be used where the function
           is called by a user command, which it should not return.
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         self.writeout_cache()
         if not include_latest:
             n += 1
         cur = self._run_sql("ORDER BY session DESC, line DESC LIMIT ?",
                                 (n,), raw=raw, output=output)
         if not include_latest:
             return reversed(list(cur)[1:])
         return reversed(list(cur))
 
     @catch_corrupt_db
     def search(self, pattern="*", raw=True, search_raw=True,
                output=False, n=None, unique=False):
         """Search the database using unix glob-style matching (wildcards
         * and ?).
 
         Parameters
         ----------
         pattern : str
           The wildcarded pattern to match when searching
         search_raw : bool
           If True, search the raw input, otherwise, the parsed input
         raw, output : bool
           See :meth:`get_range`
         n : None or int
           If an integer is given, it defines the limit of
           returned entries.
         unique : bool
           When it is true, return only unique entries.
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         tosearch = "source_raw" if search_raw else "source"
         if output:
             tosearch = "history." + tosearch
         self.writeout_cache()
         sqlform = "WHERE %s GLOB ?" % tosearch
         params = (pattern,)
         if unique:
             sqlform += ' GROUP BY {0}'.format(tosearch)
         if n is not None:
             sqlform += " ORDER BY session DESC, line DESC LIMIT ?"
             params += (n,)
         elif unique:
             sqlform += " ORDER BY session, line"
         cur = self._run_sql(sqlform, params, raw=raw, output=output)
         if n is not None:
             return reversed(list(cur))
         return cur
 
     @catch_corrupt_db
     def get_range(self, session, start=1, stop=None, raw=True,output=False):
         """Retrieve input by session.
 
         Parameters
         ----------
         session : int
             Session number to retrieve.
         start : int
             First line to retrieve.
         stop : int
             End of line range (excluded from output itself). If None, retrieve
             to the end of the session.
         raw : bool
             If True, return untranslated input
         output : bool
             If True, attempt to include output. This will be 'real' Python
             objects for the current session, or text reprs from previous
             sessions if db_log_output was enabled at the time. Where no output
             is found, None is used.
 
         Returns
         -------
         entries
           An iterator over the desired lines. Each line is a 3-tuple, either
           (session, line, input) if output is False, or
           (session, line, (input, output)) if output is True.
         """
         if stop:
             lineclause = "line >= ? AND line < ?"
             params = (session, start, stop)
         else:
             lineclause = "line>=?"
             params = (session, start)
 
         return self._run_sql("WHERE session==? AND %s" % lineclause,
                                     params, raw=raw, output=output)
 
     def get_range_by_str(self, rangestr, raw=True, output=False):
         """Get lines of history from a string of ranges, as used by magic
         commands %hist, %save, %macro, etc.
 
         Parameters
         ----------
         rangestr : str
-          A string specifying ranges, e.g. "5 ~2/1-4". See
-          :func:`magic_history` for full details.
+          A string specifying ranges, e.g. "5 ~2/1-4". If empty string is used,
+          this will return everything from current session's history.
+
+          See the documentation of :func:`%history` for the full details.
+
         raw, output : bool
           As :meth:`get_range`
 
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         for sess, s, e in extract_hist_ranges(rangestr):
             for line in self.get_range(sess, s, e, raw=raw, output=output):
                 yield line
 
 
 class HistoryManager(HistoryAccessor):
     """A class to organize all history-related functionality in one place.
     """
     # Public interface
 
     # An instance of the IPython shell we are attached to
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
                      allow_none=True)
     # Lists to hold processed and raw history. These start with a blank entry
     # so that we can index them starting from 1
     input_hist_parsed = List([""])
     input_hist_raw = List([""])
     # A list of directories visited during session
     dir_hist = List()
     @default('dir_hist')
     def _dir_hist_default(self):
         try:
             return [Path.cwd()]
         except OSError:
             return []
 
     # A dict of output history, keyed with ints from the shell's
     # execution count.
     output_hist = Dict()
     # The text/plain repr of outputs.
     output_hist_reprs = Dict()
 
     # The number of the current session in the history database
     session_number = Integer()
 
     db_log_output = Bool(False,
         help="Should the history database include output? (default: no)"
     ).tag(config=True)
     db_cache_size = Integer(0,
         help="Write to database every x commands (higher values save disk access & power).\n"
         "Values of 1 or less effectively disable caching."
     ).tag(config=True)
     # The input and output caches
     db_input_cache = List()
     db_output_cache = List()
 
     # History saving in separate thread
     save_thread = Instance('IPython.core.history.HistorySavingThread',
                            allow_none=True)
     save_flag = Instance(threading.Event, allow_none=True)
 
     # Private interface
     # Variables used to store the three last inputs from the user.  On each new
     # history update, we populate the user's namespace with these, shifted as
     # necessary.
     _i00 = Unicode(u'')
     _i = Unicode(u'')
     _ii = Unicode(u'')
     _iii = Unicode(u'')
 
     # A regex matching all forms of the exit command, so that we don't store
     # them in the history (it's annoying to rewind the first entry and land on
     # an exit call).
     _exit_re = re.compile(r"(exit|quit)(\s*\(.*\))?$")
 
     def __init__(self, shell=None, config=None, **traits):
         """Create a new history manager associated with a shell instance.
         """
         # We need a pointer back to the shell for various tasks.
         super(HistoryManager, self).__init__(shell=shell, config=config,
             **traits)
         self.save_flag = threading.Event()
         self.db_input_cache_lock = threading.Lock()
         self.db_output_cache_lock = threading.Lock()
 
         try:
             self.new_session()
         except sqlite3.OperationalError:
             self.log.error("Failed to create history session in %s. History will not be saved.",
                 self.hist_file, exc_info=True)
             self.hist_file = ':memory:'
 
         if self.enabled and self.hist_file != ':memory:':
             self.save_thread = HistorySavingThread(self)
             self.save_thread.start()
 
     def _get_hist_file_name(self, profile=None):
         """Get default history file name based on the Shell's profile.
 
         The profile parameter is ignored, but must exist for compatibility with
         the parent class."""
         profile_dir = self.shell.profile_dir.location
         return Path(profile_dir) / "history.sqlite"
 
     @only_when_enabled
     def new_session(self, conn=None):
         """Get a new session number."""
         if conn is None:
             conn = self.db
 
         with conn:
             cur = conn.execute("""INSERT INTO sessions VALUES (NULL, ?, NULL,
                             NULL, "") """, (datetime.datetime.now(),))
             self.session_number = cur.lastrowid
 
     def end_session(self):
         """Close the database session, filling in the end time and line count."""
         self.writeout_cache()
         with self.db:
             self.db.execute("""UPDATE sessions SET end=?, num_cmds=? WHERE
                             session==?""", (datetime.datetime.now(),
                             len(self.input_hist_parsed)-1, self.session_number))
         self.session_number = 0
 
     def name_session(self, name):
         """Give the current session a name in the history database."""
         with self.db:
             self.db.execute("UPDATE sessions SET remark=? WHERE session==?",
                             (name, self.session_number))
 
     def reset(self, new_session=True):
         """Clear the session history, releasing all object references, and
         optionally open a new session."""
         self.output_hist.clear()
         # The directory history can't be completely empty
         self.dir_hist[:] = [Path.cwd()]
 
         if new_session:
             if self.session_number:
                 self.end_session()
             self.input_hist_parsed[:] = [""]
             self.input_hist_raw[:] = [""]
             self.new_session()
 
     # ------------------------------
     # Methods for retrieving history
     # ------------------------------
     def get_session_info(self, session=0):
         """Get info about a session.
 
         Parameters
         ----------
 
         session : int
             Session number to retrieve. The current session is 0, and negative
             numbers count back from current session, so -1 is the previous session.
 
         Returns
         -------
 
         session_id : int
            Session ID number
         start : datetime
            Timestamp for the start of the session.
         end : datetime
            Timestamp for the end of the session, or None if IPython crashed.
         num_cmds : int
            Number of commands run, or None if IPython crashed.
         remark : unicode
            A manually set description.
         """
         if session <= 0:
             session += self.session_number
 
         return super(HistoryManager, self).get_session_info(session=session)
 
     def _get_range_session(self, start=1, stop=None, raw=True, output=False):
         """Get input and output history from the current session. Called by
         get_range, and takes similar parameters."""
         input_hist = self.input_hist_raw if raw else self.input_hist_parsed
 
         n = len(input_hist)
         if start < 0:
             start += n
         if not stop or (stop > n):
             stop = n
         elif stop < 0:
             stop += n
 
         for i in range(start, stop):
             if output:
                 line = (input_hist[i], self.output_hist_reprs.get(i))
             else:
                 line = input_hist[i]
             yield (0, i, line)
 
     def get_range(self, session=0, start=1, stop=None, raw=True,output=False):
         """Retrieve input by session.
 
         Parameters
         ----------
         session : int
             Session number to retrieve. The current session is 0, and negative
             numbers count back from current session, so -1 is previous session.
         start : int
             First line to retrieve.
         stop : int
             End of line range (excluded from output itself). If None, retrieve
             to the end of the session.
         raw : bool
             If True, return untranslated input
         output : bool
             If True, attempt to include output. This will be 'real' Python
             objects for the current session, or text reprs from previous
             sessions if db_log_output was enabled at the time. Where no output
             is found, None is used.
 
         Returns
         -------
         entries
           An iterator over the desired lines. Each line is a 3-tuple, either
           (session, line, input) if output is False, or
           (session, line, (input, output)) if output is True.
         """
         if session <= 0:
             session += self.session_number
         if session==self.session_number:          # Current session
             return self._get_range_session(start, stop, raw, output)
         return super(HistoryManager, self).get_range(session, start, stop, raw,
                                                      output)
 
     ## ----------------------------
     ## Methods for storing history:
     ## ----------------------------
     def store_inputs(self, line_num, source, source_raw=None):
         """Store source and raw input in history and create input cache
         variables ``_i*``.
 
         Parameters
         ----------
         line_num : int
           The prompt number of this input.
 
         source : str
           Python input.
 
         source_raw : str, optional
           If given, this is the raw input without any IPython transformations
           applied to it.  If not given, ``source`` is used.
         """
         if source_raw is None:
             source_raw = source
         source = source.rstrip('\n')
         source_raw = source_raw.rstrip('\n')
 
         # do not store exit/quit commands
         if self._exit_re.match(source_raw.strip()):
             return
 
         self.input_hist_parsed.append(source)
         self.input_hist_raw.append(source_raw)
 
         with self.db_input_cache_lock:
             self.db_input_cache.append((line_num, source, source_raw))
             # Trigger to flush cache and write to DB.
             if len(self.db_input_cache) >= self.db_cache_size:
                 self.save_flag.set()
 
         # update the auto _i variables
         self._iii = self._ii
         self._ii = self._i
         self._i = self._i00
         self._i00 = source_raw
 
         # hackish access to user namespace to create _i1,_i2... dynamically
         new_i = '_i%s' % line_num
         to_main = {'_i': self._i,
                    '_ii': self._ii,
                    '_iii': self._iii,
                    new_i : self._i00 }
 
         if self.shell is not None:
             self.shell.push(to_main, interactive=False)
 
     def store_output(self, line_num):
         """If database output logging is enabled, this saves all the
         outputs from the indicated prompt number to the database. It's
         called by run_cell after code has been executed.
 
         Parameters
         ----------
         line_num : int
           The line number from which to save outputs
         """
         if (not self.db_log_output) or (line_num not in self.output_hist_reprs):
             return
         output = self.output_hist_reprs[line_num]
 
         with self.db_output_cache_lock:
             self.db_output_cache.append((line_num, output))
         if self.db_cache_size <= 1:
             self.save_flag.set()
 
     def _writeout_input_cache(self, conn):
         with conn:
             for line in self.db_input_cache:
                 conn.execute("INSERT INTO history VALUES (?, ?, ?, ?)",
                                 (self.session_number,)+line)
 
     def _writeout_output_cache(self, conn):
         with conn:
             for line in self.db_output_cache:
                 conn.execute("INSERT INTO output_history VALUES (?, ?, ?)",
                                 (self.session_number,)+line)
 
     @only_when_enabled
     def writeout_cache(self, conn=None):
         """Write any entries in the cache to the database."""
         if conn is None:
             conn = self.db
 
         with self.db_input_cache_lock:
             try:
                 self._writeout_input_cache(conn)
             except sqlite3.IntegrityError:
                 self.new_session(conn)
                 print("ERROR! Session/line number was not unique in",
                       "database. History logging moved to new session",
                                                 self.session_number)
                 try:
                     # Try writing to the new session. If this fails, don't
                     # recurse
                     self._writeout_input_cache(conn)
                 except sqlite3.IntegrityError:
                     pass
             finally:
                 self.db_input_cache = []
 
         with self.db_output_cache_lock:
             try:
                 self._writeout_output_cache(conn)
             except sqlite3.IntegrityError:
                 print("!! Session/line number for output was not unique",
                       "in database. Output will not be stored.")
             finally:
                 self.db_output_cache = []
 
 
 class HistorySavingThread(threading.Thread):
     """This thread takes care of writing history to the database, so that
     the UI isn't held up while that happens.
 
     It waits for the HistoryManager's save_flag to be set, then writes out
     the history cache. The main thread is responsible for setting the flag when
     the cache size reaches a defined threshold."""
     daemon = True
     stop_now = False
     enabled = True
     def __init__(self, history_manager):
         super(HistorySavingThread, self).__init__(name="IPythonHistorySavingThread")
         self.history_manager = history_manager
         self.enabled = history_manager.enabled
         atexit.register(self.stop)
 
     @only_when_enabled
     def run(self):
         # We need a separate db connection per thread:
         try:
             self.db = sqlite3.connect(
                 str(self.history_manager.hist_file),
                 **self.history_manager.connection_options
             )
             while True:
                 self.history_manager.save_flag.wait()
                 if self.stop_now:
                     self.db.close()
                     return
                 self.history_manager.save_flag.clear()
                 self.history_manager.writeout_cache(self.db)
         except Exception as e:
             print(("The history saving thread hit an unexpected error (%s)."
                    "History will not be written to the database.") % repr(e))
 
     def stop(self):
         """This can be called from the main thread to safely stop this thread.
 
         Note that it does not attempt to write out remaining history before
         exiting. That should be done by calling the HistoryManager's
         end_session method."""
         self.stop_now = True
         self.history_manager.save_flag.set()
         self.join()
 
 
 # To match, e.g. ~5/8-~2/3
 range_re = re.compile(r"""
 ((?P<startsess>~?\d+)/)?
 (?P<start>\d+)?
 ((?P<sep>[\-:])
  ((?P<endsess>~?\d+)/)?
  (?P<end>\d+))?
 $""", re.VERBOSE)
 
 
 def extract_hist_ranges(ranges_str):
     """Turn a string of history ranges into 3-tuples of (session, start, stop).
 
+    Empty string results in a `[(0, 1, None)]`, i.e. "everything from current
+    session".
+
     Examples
     --------
     >>> list(extract_hist_ranges("~8/5-~7/4 2"))
     [(-8, 5, None), (-7, 1, 5), (0, 2, 3)]
     """
+    if ranges_str == "":
+        yield (0, 1, None)  # Everything from current session
+        return
+
     for range_str in ranges_str.split():
         rmatch = range_re.match(range_str)
         if not rmatch:
             continue
         start = rmatch.group("start")
         if start:
             start = int(start)
             end = rmatch.group("end")
             # If no end specified, get (a, a + 1)
             end = int(end) if end else start + 1
         else:  # start not specified
             if not rmatch.group('startsess'):  # no startsess
                 continue
             start = 1
             end = None  # provide the entire session hist
 
         if rmatch.group("sep") == "-":       # 1-3 == 1:4 --> [1, 2, 3]
             end += 1
         startsess = rmatch.group("startsess") or "0"
         endsess = rmatch.group("endsess") or startsess
         startsess = int(startsess.replace("~","-"))
         endsess = int(endsess.replace("~","-"))
         assert endsess >= startsess, "start session must be earlier than end session"
 
         if endsess == startsess:
             yield (startsess, start, end)
             continue
         # Multiple sessions in one range:
         yield (startsess, start, None)
         for sess in range(startsess+1, endsess):
             yield (sess, 1, None)
         yield (endsess, 1, end)
 
 
 def _format_lineno(session, line):
     """Helper function to format line numbers properly."""
     if session == 0:
         return str(line)
     return "%s#%s" % (session, line)

IPython/core/interactiveshell.py

@@ -1,3867 +1,3880 b''
 # -*- coding: utf-8 -*-
 """Main IPython class."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2001 Janko Hauser <[e-mail]>
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #  Copyright (C) 2008-2011  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 
 import abc
 import ast
 import atexit
 import builtins as builtin_mod
 import functools
 import inspect
 import os
 import re
 import runpy
 import sys
 import tempfile
 import traceback
 import types
 import subprocess
 import warnings
 from io import open as io_open
 
 from pathlib import Path
 from pickleshare import PickleShareDB
 
 from traitlets.config.configurable import SingletonConfigurable
 from traitlets.utils.importstring import import_item
 from IPython.core import oinspect
 from IPython.core import magic
 from IPython.core import page
 from IPython.core import prefilter
 from IPython.core import ultratb
 from IPython.core.alias import Alias, AliasManager
 from IPython.core.autocall import ExitAutocall
 from IPython.core.builtin_trap import BuiltinTrap
 from IPython.core.events import EventManager, available_events
 from IPython.core.compilerop import CachingCompiler, check_linecache_ipython
 from IPython.core.debugger import Pdb
 from IPython.core.display_trap import DisplayTrap
 from IPython.core.displayhook import DisplayHook
 from IPython.core.displaypub import DisplayPublisher
 from IPython.core.error import InputRejected, UsageError
 from IPython.core.extensions import ExtensionManager
 from IPython.core.formatters import DisplayFormatter
 from IPython.core.history import HistoryManager
 from IPython.core.inputtransformer2 import ESC_MAGIC, ESC_MAGIC2
 from IPython.core.logger import Logger
 from IPython.core.macro import Macro
 from IPython.core.payload import PayloadManager
 from IPython.core.prefilter import PrefilterManager
 from IPython.core.profiledir import ProfileDir
 from IPython.core.usage import default_banner
 from IPython.display import display
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import PyColorize
 from IPython.utils import io
 from IPython.utils import py3compat
 from IPython.utils import openpy
 from IPython.utils.decorators import undoc
 from IPython.utils.io import ask_yes_no
 from IPython.utils.ipstruct import Struct
 from IPython.paths import get_ipython_dir
 from IPython.utils.path import get_home_dir, get_py_filename, ensure_dir_exists
 from IPython.utils.process import system, getoutput
 from IPython.utils.strdispatch import StrDispatch
 from IPython.utils.syspathcontext import prepended_to_syspath
 from IPython.utils.text import format_screen, LSString, SList, DollarFormatter
 from IPython.utils.tempdir import TemporaryDirectory
 from traitlets import (
     Integer, Bool, CaselessStrEnum, Enum, List, Dict, Unicode, Instance, Type,
     observe, default, validate, Any
 )
 from warnings import warn
 from logging import error
 import IPython.core.hooks
 
 from typing import List as ListType, Tuple, Optional
 from ast import AST
 
 # NoOpContext is deprecated, but ipykernel imports it from here.
 # See https://github.com/ipython/ipykernel/issues/157
 # (2016, let's try to remove than in IPython 8.0)
 from IPython.utils.contexts import NoOpContext
 
 try:
     import docrepr.sphinxify as sphx
 
     def sphinxify(doc):
         with TemporaryDirectory() as dirname:
             return {
                 'text/html': sphx.sphinxify(doc, dirname),
                 'text/plain': doc
             }
 except ImportError:
     sphinxify = None
 
 
 class ProvisionalWarning(DeprecationWarning):
     """
     Warning class for unstable features
     """
     pass
 
 if sys.version_info > (3,8):
     from ast import Module
 else :
     # mock the new API, ignore second argument
     # see https://github.com/ipython/ipython/issues/11590
     from ast import Module as OriginalModule
     Module = lambda nodelist, type_ignores: OriginalModule(nodelist)
 
 if sys.version_info > (3,6):
     _assign_nodes         = (ast.AugAssign, ast.AnnAssign, ast.Assign)
     _single_targets_nodes = (ast.AugAssign, ast.AnnAssign)
 else:
     _assign_nodes         = (ast.AugAssign, ast.Assign )
     _single_targets_nodes = (ast.AugAssign, )
 
 #-----------------------------------------------------------------------------
 # Await Helpers
 #-----------------------------------------------------------------------------
 
 def removed_co_newlocals(function:types.FunctionType) -> types.FunctionType:
     """Return a function that do not create a new local scope.
 
     Given a function, create a clone of this function where the co_newlocal flag
     has been removed, making this function code actually run in the sourounding
     scope.
 
     We need this in order to run asynchronous code in user level namespace.
     """
     from types import CodeType, FunctionType
     CO_NEWLOCALS = 0x0002
     code = function.__code__
     new_co_flags = code.co_flags & ~CO_NEWLOCALS
     if sys.version_info > (3, 8, 0, 'alpha', 3):
         new_code = code.replace(co_flags=new_co_flags)
     else:
         new_code = CodeType(
             code.co_argcount,
             code.co_kwonlyargcount,
             code.co_nlocals,
             code.co_stacksize,
             new_co_flags,
             code.co_code,
             code.co_consts,
             code.co_names,
             code.co_varnames,
             code.co_filename,
             code.co_name,
             code.co_firstlineno,
             code.co_lnotab,
             code.co_freevars,
             code.co_cellvars
         )
     return FunctionType(new_code, globals(), function.__name__, function.__defaults__)
 
 
 # we still need to run things using the asyncio eventloop, but there is no
 # async integration
 from .async_helpers import (_asyncio_runner,  _asyncify, _pseudo_sync_runner)
 from .async_helpers import _curio_runner, _trio_runner, _should_be_async
 
 
 def _ast_asyncify(cell:str, wrapper_name:str) -> ast.Module:
     """
     Parse a cell with top-level await and modify the AST to be able to run it later.
 
     Parameters
     ----------
     cell: str
         The code cell to asyncronify
     wrapper_name: str
         The name of the function to be used to wrap the passed `cell`. It is
         advised to **not** use a python identifier in order to not pollute the
         global namespace in which the function will be ran.
 
     Returns
     -------
     ModuleType:
         A module object AST containing **one** function named `wrapper_name`.
 
         The given code is wrapped in a async-def function, parsed into an AST, and
         the resulting function definition AST is modified to return the last
         expression.
 
         The last expression or await node is moved into a return statement at the
         end of the function, and removed from its original location. If the last
         node is not Expr or Await nothing is done.
 
         The function `__code__` will need to be later modified  (by
         ``removed_co_newlocals``) in a subsequent step to not create new `locals()`
         meaning that the local and global scope are the same, ie as if the body of
         the function was at module level.
 
         Lastly a call to `locals()` is made just before the last expression of the
         function, or just after the last assignment or statement to make sure the
         global dict is updated as python function work with a local fast cache which
         is updated only on `local()` calls.
     """
 
     from ast import Expr, Await, Return
     if sys.version_info >= (3,8):
         return ast.parse(cell)
     tree = ast.parse(_asyncify(cell))
 
     function_def = tree.body[0]
     function_def.name = wrapper_name
     try_block = function_def.body[0]
     lastexpr = try_block.body[-1]
     if isinstance(lastexpr, (Expr, Await)):
         try_block.body[-1] = Return(lastexpr.value)
     ast.fix_missing_locations(tree)
     return tree
 #-----------------------------------------------------------------------------
 # Globals
 #-----------------------------------------------------------------------------
 
 # compiled regexps for autoindent management
 dedent_re = re.compile(r'^\s+raise|^\s+return|^\s+pass')
 
 #-----------------------------------------------------------------------------
 # Utilities
 #-----------------------------------------------------------------------------
 
 @undoc
 def softspace(file, newvalue):
     """Copied from code.py, to remove the dependency"""
 
     oldvalue = 0
     try:
         oldvalue = file.softspace
     except AttributeError:
         pass
     try:
         file.softspace = newvalue
     except (AttributeError, TypeError):
         # "attribute-less object" or "read-only attributes"
         pass
     return oldvalue
 
 @undoc
 def no_op(*a, **kw):
     pass
 
 
 class SpaceInInput(Exception): pass
 
 
 def get_default_colors():
     "DEPRECATED"
     warn('get_default_color is deprecated since IPython 5.0, and returns `Neutral` on all platforms.',
         DeprecationWarning, stacklevel=2)
     return 'Neutral'
 
 
 class SeparateUnicode(Unicode):
     r"""A Unicode subclass to validate separate_in, separate_out, etc.
 
     This is a Unicode based trait that converts '0'->'' and ``'\\n'->'\n'``.
     """
 
     def validate(self, obj, value):
         if value == '0': value = ''
         value = value.replace('\\n','\n')
         return super(SeparateUnicode, self).validate(obj, value)
 
 
 @undoc
 class DummyMod(object):
     """A dummy module used for IPython's interactive module when
     a namespace must be assigned to the module's __dict__."""
     __spec__ = None
 
 
 class ExecutionInfo(object):
     """The arguments used for a call to :meth:`InteractiveShell.run_cell`
 
     Stores information about what is going to happen.
     """
     raw_cell = None
     store_history = False
     silent = False
     shell_futures = True
 
     def __init__(self, raw_cell, store_history, silent, shell_futures):
         self.raw_cell = raw_cell
         self.store_history = store_history
         self.silent = silent
         self.shell_futures = shell_futures
 
     def __repr__(self):
         name = self.__class__.__qualname__
         raw_cell = ((self.raw_cell[:50] + '..')
                     if len(self.raw_cell) > 50 else self.raw_cell)
         return '<%s object at %x, raw_cell="%s" store_history=%s silent=%s shell_futures=%s>' %\
                (name, id(self), raw_cell, self.store_history, self.silent, self.shell_futures)
 
 
 class ExecutionResult(object):
     """The result of a call to :meth:`InteractiveShell.run_cell`
 
     Stores information about what took place.
     """
     execution_count = None
     error_before_exec = None
     error_in_exec = None
     info = None
     result = None
 
     def __init__(self, info):
         self.info = info
 
     @property
     def success(self):
         return (self.error_before_exec is None) and (self.error_in_exec is None)
 
     def raise_error(self):
         """Reraises error if `success` is `False`, otherwise does nothing"""
         if self.error_before_exec is not None:
             raise self.error_before_exec
         if self.error_in_exec is not None:
             raise self.error_in_exec
 
     def __repr__(self):
         name = self.__class__.__qualname__
         return '<%s object at %x, execution_count=%s error_before_exec=%s error_in_exec=%s info=%s result=%s>' %\
                 (name, id(self), self.execution_count, self.error_before_exec, self.error_in_exec, repr(self.info), repr(self.result))
 
 
 class InteractiveShell(SingletonConfigurable):
     """An enhanced, interactive shell for Python."""
 
     _instance = None
 
     ast_transformers = List([], help=
         """
         A list of ast.NodeTransformer subclass instances, which will be applied
         to user input before code is run.
         """
     ).tag(config=True)
 
     autocall = Enum((0,1,2), default_value=0, help=
         """
         Make IPython automatically call any callable object even if you didn't
         type explicit parentheses. For example, 'str 43' becomes 'str(43)'
         automatically. The value can be '0' to disable the feature, '1' for
         'smart' autocall, where it is not applied if there are no more
         arguments on the line, and '2' for 'full' autocall, where all callable
         objects are automatically called (even if no arguments are present).
         """
     ).tag(config=True)
 
     autoindent = Bool(True, help=
         """
         Autoindent IPython code entered interactively.
         """
     ).tag(config=True)
 
     autoawait = Bool(True, help=
         """
         Automatically run await statement in the top level repl.
         """
     ).tag(config=True)
 
     loop_runner_map ={
         'asyncio':(_asyncio_runner, True),
         'curio':(_curio_runner, True),
         'trio':(_trio_runner, True),
         'sync': (_pseudo_sync_runner, False)
     }
 
     loop_runner = Any(default_value="IPython.core.interactiveshell._asyncio_runner",
         allow_none=True,
         help="""Select the loop runner that will be used to execute top-level asynchronous code"""
     ).tag(config=True)
 
     @default('loop_runner')
     def _default_loop_runner(self):
         return import_item("IPython.core.interactiveshell._asyncio_runner")
 
     @validate('loop_runner')
     def _import_runner(self, proposal):
         if isinstance(proposal.value, str):
             if proposal.value in self.loop_runner_map:
                 runner, autoawait = self.loop_runner_map[proposal.value]
                 self.autoawait = autoawait
                 return runner
             runner = import_item(proposal.value)
             if not callable(runner):
                 raise ValueError('loop_runner must be callable')
             return runner
         if not callable(proposal.value):
             raise ValueError('loop_runner must be callable')
         return proposal.value
 
     automagic = Bool(True, help=
         """
         Enable magic commands to be called without the leading %.
         """
     ).tag(config=True)
 
     banner1 = Unicode(default_banner,
         help="""The part of the banner to be printed before the profile"""
     ).tag(config=True)
     banner2 = Unicode('',
         help="""The part of the banner to be printed after the profile"""
     ).tag(config=True)
 
     cache_size = Integer(1000, help=
         """
         Set the size of the output cache.  The default is 1000, you can
         change it permanently in your config file.  Setting it to 0 completely
         disables the caching system, and the minimum value accepted is 3 (if
         you provide a value less than 3, it is reset to 0 and a warning is
         issued).  This limit is defined because otherwise you'll spend more
         time re-flushing a too small cache than working
         """
     ).tag(config=True)
     color_info = Bool(True, help=
         """
         Use colors for displaying information about objects. Because this
         information is passed through a pager (like 'less'), and some pagers
         get confused with color codes, this capability can be turned off.
         """
     ).tag(config=True)
     colors = CaselessStrEnum(('Neutral', 'NoColor','LightBG','Linux'),
                              default_value='Neutral',
         help="Set the color scheme (NoColor, Neutral, Linux, or LightBG)."
     ).tag(config=True)
     debug = Bool(False).tag(config=True)
     disable_failing_post_execute = Bool(False,
         help="Don't call post-execute functions that have failed in the past."
     ).tag(config=True)
     display_formatter = Instance(DisplayFormatter, allow_none=True)
     displayhook_class = Type(DisplayHook)
     display_pub_class = Type(DisplayPublisher)
     compiler_class = Type(CachingCompiler)
 
     sphinxify_docstring = Bool(False, help=
         """
         Enables rich html representation of docstrings. (This requires the
         docrepr module).
         """).tag(config=True)
 
     @observe("sphinxify_docstring")
     def _sphinxify_docstring_changed(self, change):
         if change['new']:
             warn("`sphinxify_docstring` is provisional since IPython 5.0 and might change in future versions." , ProvisionalWarning)
 
     enable_html_pager = Bool(False, help=
         """
         (Provisional API) enables html representation in mime bundles sent
         to pagers.
         """).tag(config=True)
 
     @observe("enable_html_pager")
     def _enable_html_pager_changed(self, change):
         if change['new']:
             warn("`enable_html_pager` is provisional since IPython 5.0 and might change in future versions.", ProvisionalWarning)
 
     data_pub_class = None
 
     exit_now = Bool(False)
     exiter = Instance(ExitAutocall)
     @default('exiter')
     def _exiter_default(self):
         return ExitAutocall(self)
     # Monotonically increasing execution counter
     execution_count = Integer(1)
     filename = Unicode("<ipython console>")
     ipython_dir= Unicode('').tag(config=True) # Set to get_ipython_dir() in __init__
 
     # Used to transform cells before running them, and check whether code is complete
     input_transformer_manager = Instance('IPython.core.inputtransformer2.TransformerManager',
                                          ())
 
     @property
     def input_transformers_cleanup(self):
         return self.input_transformer_manager.cleanup_transforms
 
     input_transformers_post = List([],
         help="A list of string input transformers, to be applied after IPython's "
              "own input transformations."
     )
 
     @property
     def input_splitter(self):
         """Make this available for backward compatibility (pre-7.0 release) with existing code.
 
         For example, ipykernel ipykernel currently uses
         `shell.input_splitter.check_complete`
         """
         from warnings import warn
         warn("`input_splitter` is deprecated since IPython 7.0, prefer `input_transformer_manager`.",
              DeprecationWarning, stacklevel=2
         )
         return self.input_transformer_manager
 
     logstart = Bool(False, help=
         """
         Start logging to the default log file in overwrite mode.
         Use `logappend` to specify a log file to **append** logs to.
         """
     ).tag(config=True)
     logfile = Unicode('', help=
         """
         The name of the logfile to use.
         """
     ).tag(config=True)
     logappend = Unicode('', help=
         """
         Start logging to the given file in append mode.
         Use `logfile` to specify a log file to **overwrite** logs to.
         """
     ).tag(config=True)
     object_info_string_level = Enum((0,1,2), default_value=0,
     ).tag(config=True)
     pdb = Bool(False, help=
         """
         Automatically call the pdb debugger after every exception.
         """
     ).tag(config=True)
     display_page = Bool(False,
         help="""If True, anything that would be passed to the pager
         will be displayed as regular output instead."""
     ).tag(config=True)
 
     # deprecated prompt traits:
 
     prompt_in1 = Unicode('In [\\#]: ',
         help="Deprecated since IPython 4.0 and ignored since 5.0, set TerminalInteractiveShell.prompts object directly."
     ).tag(config=True)
     prompt_in2 = Unicode('   .\\D.: ',
         help="Deprecated since IPython 4.0 and ignored since 5.0, set TerminalInteractiveShell.prompts object directly."
     ).tag(config=True)
     prompt_out = Unicode('Out[\\#]: ',
         help="Deprecated since IPython 4.0 and ignored since 5.0, set TerminalInteractiveShell.prompts object directly."
     ).tag(config=True)
     prompts_pad_left = Bool(True,
         help="Deprecated since IPython 4.0 and ignored since 5.0, set TerminalInteractiveShell.prompts object directly."
     ).tag(config=True)
 
     @observe('prompt_in1', 'prompt_in2', 'prompt_out', 'prompt_pad_left')
     def _prompt_trait_changed(self, change):
         name = change['name']
         warn("InteractiveShell.{name} is deprecated since IPython 4.0"
              " and ignored since 5.0, set TerminalInteractiveShell.prompts"
              " object directly.".format(name=name))
 
         # protect against weird cases where self.config may not exist:
 
     show_rewritten_input = Bool(True,
         help="Show rewritten input, e.g. for autocall."
     ).tag(config=True)
 
     quiet = Bool(False).tag(config=True)
 
     history_length = Integer(10000,
         help='Total length of command history'
     ).tag(config=True)
 
     history_load_length = Integer(1000, help=
         """
         The number of saved history entries to be loaded
         into the history buffer at startup.
         """
     ).tag(config=True)
 
     ast_node_interactivity = Enum(['all', 'last', 'last_expr', 'none', 'last_expr_or_assign'],
                                   default_value='last_expr',
                                   help="""
         'all', 'last', 'last_expr' or 'none', 'last_expr_or_assign' specifying
         which nodes should be run interactively (displaying output from expressions).
         """
     ).tag(config=True)
 
     # TODO: this part of prompt management should be moved to the frontends.
     # Use custom TraitTypes that convert '0'->'' and '\\n'->'\n'
     separate_in = SeparateUnicode('\n').tag(config=True)
     separate_out = SeparateUnicode('').tag(config=True)
     separate_out2 = SeparateUnicode('').tag(config=True)
     wildcards_case_sensitive = Bool(True).tag(config=True)
     xmode = CaselessStrEnum(('Context', 'Plain', 'Verbose', 'Minimal'),
                             default_value='Context',
                             help="Switch modes for the IPython exception handlers."
                             ).tag(config=True)
 
     # Subcomponents of InteractiveShell
     alias_manager = Instance('IPython.core.alias.AliasManager', allow_none=True)
     prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager', allow_none=True)
     builtin_trap = Instance('IPython.core.builtin_trap.BuiltinTrap', allow_none=True)
     display_trap = Instance('IPython.core.display_trap.DisplayTrap', allow_none=True)
     extension_manager = Instance('IPython.core.extensions.ExtensionManager', allow_none=True)
     payload_manager = Instance('IPython.core.payload.PayloadManager', allow_none=True)
     history_manager = Instance('IPython.core.history.HistoryAccessorBase', allow_none=True)
     magics_manager = Instance('IPython.core.magic.MagicsManager', allow_none=True)
 
     profile_dir = Instance('IPython.core.application.ProfileDir', allow_none=True)
     @property
     def profile(self):
         if self.profile_dir is not None:
             name = os.path.basename(self.profile_dir.location)
             return name.replace('profile_','')
 
 
     # Private interface
     _post_execute = Dict()
 
     # Tracks any GUI loop loaded for pylab
     pylab_gui_select = None
 
     last_execution_succeeded = Bool(True, help='Did last executed command succeeded')
 
     last_execution_result = Instance('IPython.core.interactiveshell.ExecutionResult', help='Result of executing the last command', allow_none=True)
 
     def __init__(self, ipython_dir=None, profile_dir=None,
                  user_module=None, user_ns=None,
                  custom_exceptions=((), None), **kwargs):
 
         # This is where traits with a config_key argument are updated
         # from the values on config.
         super(InteractiveShell, self).__init__(**kwargs)
         if 'PromptManager' in self.config:
             warn('As of IPython 5.0 `PromptManager` config will have no effect'
                  ' and has been replaced by TerminalInteractiveShell.prompts_class')
         self.configurables = [self]
 
         # These are relatively independent and stateless
         self.init_ipython_dir(ipython_dir)
         self.init_profile_dir(profile_dir)
         self.init_instance_attrs()
         self.init_environment()
 
         # Check if we're in a virtualenv, and set up sys.path.
         self.init_virtualenv()
 
         # Create namespaces (user_ns, user_global_ns, etc.)
         self.init_create_namespaces(user_module, user_ns)
         # This has to be done after init_create_namespaces because it uses
         # something in self.user_ns, but before init_sys_modules, which
         # is the first thing to modify sys.
         # TODO: When we override sys.stdout and sys.stderr before this class
         # is created, we are saving the overridden ones here. Not sure if this
         # is what we want to do.
         self.save_sys_module_state()
         self.init_sys_modules()
 
         # While we're trying to have each part of the code directly access what
         # it needs without keeping redundant references to objects, we have too
         # much legacy code that expects ip.db to exist.
         self.db = PickleShareDB(os.path.join(self.profile_dir.location, 'db'))
 
         self.init_history()
         self.init_encoding()
         self.init_prefilter()
 
         self.init_syntax_highlighting()
         self.init_hooks()
         self.init_events()
         self.init_pushd_popd_magic()
         self.init_user_ns()
         self.init_logger()
         self.init_builtins()
 
         # The following was in post_config_initialization
         self.init_inspector()
         self.raw_input_original = input
         self.init_completer()
         # TODO: init_io() needs to happen before init_traceback handlers
         # because the traceback handlers hardcode the stdout/stderr streams.
         # This logic in in debugger.Pdb and should eventually be changed.
         self.init_io()
         self.init_traceback_handlers(custom_exceptions)
         self.init_prompts()
         self.init_display_formatter()
         self.init_display_pub()
         self.init_data_pub()
         self.init_displayhook()
         self.init_magics()
         self.init_alias()
         self.init_logstart()
         self.init_pdb()
         self.init_extension_manager()
         self.init_payload()
         self.init_deprecation_warnings()
         self.hooks.late_startup_hook()
         self.events.trigger('shell_initialized', self)
         atexit.register(self.atexit_operations)
 
         # The trio runner is used for running Trio in the foreground thread. It
         # is different from `_trio_runner(async_fn)` in `async_helpers.py`
         # which calls `trio.run()` for every cell. This runner runs all cells
         # inside a single Trio event loop. If used, it is set from
         # `ipykernel.kernelapp`.
         self.trio_runner = None
 
     def get_ipython(self):
         """Return the currently running IPython instance."""
         return self
 
     #-------------------------------------------------------------------------
     # Trait changed handlers
     #-------------------------------------------------------------------------
     @observe('ipython_dir')
     def _ipython_dir_changed(self, change):
         ensure_dir_exists(change['new'])
 
     def set_autoindent(self,value=None):
         """Set the autoindent flag.
 
         If called with no arguments, it acts as a toggle."""
         if value is None:
             self.autoindent = not self.autoindent
         else:
             self.autoindent = value
 
     def set_trio_runner(self, tr):
         self.trio_runner = tr
 
     #-------------------------------------------------------------------------
     # init_* methods called by __init__
     #-------------------------------------------------------------------------
 
     def init_ipython_dir(self, ipython_dir):
         if ipython_dir is not None:
             self.ipython_dir = ipython_dir
             return
 
         self.ipython_dir = get_ipython_dir()
 
     def init_profile_dir(self, profile_dir):
         if profile_dir is not None:
             self.profile_dir = profile_dir
             return
         self.profile_dir = ProfileDir.create_profile_dir_by_name(
             self.ipython_dir, "default"
         )
 
     def init_instance_attrs(self):
         self.more = False
 
         # command compiler
         self.compile = self.compiler_class()
 
         # Make an empty namespace, which extension writers can rely on both
         # existing and NEVER being used by ipython itself.  This gives them a
         # convenient location for storing additional information and state
         # their extensions may require, without fear of collisions with other
         # ipython names that may develop later.
         self.meta = Struct()
 
         # Temporary files used for various purposes.  Deleted at exit.
         # The files here are stored with Path from Pathlib
         self.tempfiles = []
         self.tempdirs = []
 
         # keep track of where we started running (mainly for crash post-mortem)
         # This is not being used anywhere currently.
         self.starting_dir = os.getcwd()
 
         # Indentation management
         self.indent_current_nsp = 0
 
         # Dict to track post-execution functions that have been registered
         self._post_execute = {}
 
     def init_environment(self):
         """Any changes we need to make to the user's environment."""
         pass
 
     def init_encoding(self):
         # Get system encoding at startup time.  Certain terminals (like Emacs
         # under Win32 have it set to None, and we need to have a known valid
         # encoding to use in the raw_input() method
         try:
             self.stdin_encoding = sys.stdin.encoding or 'ascii'
         except AttributeError:
             self.stdin_encoding = 'ascii'
 
 
     @observe('colors')
     def init_syntax_highlighting(self, changes=None):
         # Python source parser/formatter for syntax highlighting
         pyformat = PyColorize.Parser(style=self.colors, parent=self).format
         self.pycolorize = lambda src: pyformat(src,'str')
 
     def refresh_style(self):
         # No-op here, used in subclass
         pass
 
     def init_pushd_popd_magic(self):
         # for pushd/popd management
         self.home_dir = get_home_dir()
 
         self.dir_stack = []
 
     def init_logger(self):
         self.logger = Logger(self.home_dir, logfname='ipython_log.py',
                              logmode='rotate')
 
     def init_logstart(self):
         """Initialize logging in case it was requested at the command line.
         """
         if self.logappend:
             self.magic('logstart %s append' % self.logappend)
         elif self.logfile:
             self.magic('logstart %s' % self.logfile)
         elif self.logstart:
             self.magic('logstart')
 
     def init_deprecation_warnings(self):
         """
         register default filter for deprecation warning.
 
         This will allow deprecation warning of function used interactively to show
         warning to users, and still hide deprecation warning from libraries import.
         """
         if sys.version_info < (3,7):
             warnings.filterwarnings("default", category=DeprecationWarning, module=self.user_ns.get("__name__"))
 
 
     def init_builtins(self):
         # A single, static flag that we set to True.  Its presence indicates
         # that an IPython shell has been created, and we make no attempts at
         # removing on exit or representing the existence of more than one
         # IPython at a time.
         builtin_mod.__dict__['__IPYTHON__'] = True
         builtin_mod.__dict__['display'] = display
 
         self.builtin_trap = BuiltinTrap(shell=self)
 
     @observe('colors')
     def init_inspector(self, changes=None):
         # Object inspector
         self.inspector = oinspect.Inspector(oinspect.InspectColors,
                                             PyColorize.ANSICodeColors,
                                             self.colors,
                                             self.object_info_string_level)
 
     def init_io(self):
         # This will just use sys.stdout and sys.stderr. If you want to
         # override sys.stdout and sys.stderr themselves, you need to do that
         # *before* instantiating this class, because io holds onto
         # references to the underlying streams.
         # io.std* are deprecated, but don't show our own deprecation warnings
         # during initialization of the deprecated API.
         with warnings.catch_warnings():
             warnings.simplefilter('ignore', DeprecationWarning)
             io.stdout = io.IOStream(sys.stdout)
             io.stderr = io.IOStream(sys.stderr)
 
     def init_prompts(self):
         # Set system prompts, so that scripts can decide if they are running
         # interactively.
         sys.ps1 = 'In : '
         sys.ps2 = '...: '
         sys.ps3 = 'Out: '
 
     def init_display_formatter(self):
         self.display_formatter = DisplayFormatter(parent=self)
         self.configurables.append(self.display_formatter)
 
     def init_display_pub(self):
         self.display_pub = self.display_pub_class(parent=self, shell=self)
         self.configurables.append(self.display_pub)
 
     def init_data_pub(self):
         if not self.data_pub_class:
             self.data_pub = None
             return
         self.data_pub = self.data_pub_class(parent=self)
         self.configurables.append(self.data_pub)
 
     def init_displayhook(self):
         # Initialize displayhook, set in/out prompts and printing system
         self.displayhook = self.displayhook_class(
             parent=self,
             shell=self,
             cache_size=self.cache_size,
         )
         self.configurables.append(self.displayhook)
         # This is a context manager that installs/revmoes the displayhook at
         # the appropriate time.
         self.display_trap = DisplayTrap(hook=self.displayhook)
 
     def init_virtualenv(self):
         """Add the current virtualenv to sys.path so the user can import modules from it.
         This isn't perfect: it doesn't use the Python interpreter with which the
         virtualenv was built, and it ignores the --no-site-packages option. A
         warning will appear suggesting the user installs IPython in the
         virtualenv, but for many cases, it probably works well enough.
 
         Adapted from code snippets online.
 
         http://blog.ufsoft.org/2009/1/29/ipython-and-virtualenv
         """
         if 'VIRTUAL_ENV' not in os.environ:
             # Not in a virtualenv
             return
         elif os.environ["VIRTUAL_ENV"] == "":
             warn("Virtual env path set to '', please check if this is intended.")
             return
 
         p = Path(sys.executable)
         p_venv = Path(os.environ["VIRTUAL_ENV"])
 
         # fallback venv detection:
         # stdlib venv may symlink sys.executable, so we can't use realpath.
         # but others can symlink *to* the venv Python, so we can't just use sys.executable.
         # So we just check every item in the symlink tree (generally <= 3)
         paths = [p]
         while p.is_symlink():
             p = Path(os.readlink(p))
             paths.append(p.resolve())
 
         # In Cygwin paths like "c:\..." and '\cygdrive\c\...' are possible
         if str(p_venv).startswith("\\cygdrive"):
             p_venv = Path(str(p_venv)[11:])
         elif len(str(p_venv)) >= 2 and str(p_venv)[1] == ":":
             p_venv = Path(str(p_venv)[2:])
 
         if any(os.fspath(p_venv) in os.fspath(p) for p in paths):
             # Our exe is inside or has access to the virtualenv, don't need to do anything.
             return
 
         if sys.platform == "win32":
             virtual_env = Path(os.environ["VIRTUAL_ENV"], "Lib", "site-packages")
         else:
             virtual_env_path = Path(
                 os.environ["VIRTUAL_ENV"], "lib", "python{}.{}", "site-packages"
             )
             p_ver = sys.version_info[:2]
 
             # Predict version from py[thon]-x.x in the $VIRTUAL_ENV
             re_m = re.search(r"\bpy(?:thon)?([23])\.(\d+)\b", os.environ["VIRTUAL_ENV"])
             if re_m:
                 predicted_path = Path(str(virtual_env_path).format(*re_m.groups()))
                 if predicted_path.exists():
                     p_ver = re_m.groups()
 
             virtual_env = str(virtual_env_path).format(*p_ver)
 
         warn(
             "Attempting to work in a virtualenv. If you encounter problems, "
             "please install IPython inside the virtualenv."
         )
         import site
         sys.path.insert(0, virtual_env)
         site.addsitedir(virtual_env)
 
     #-------------------------------------------------------------------------
     # Things related to injections into the sys module
     #-------------------------------------------------------------------------
 
     def save_sys_module_state(self):
         """Save the state of hooks in the sys module.
 
         This has to be called after self.user_module is created.
         """
         self._orig_sys_module_state = {'stdin': sys.stdin,
                                        'stdout': sys.stdout,
                                        'stderr': sys.stderr,
                                        'excepthook': sys.excepthook}
         self._orig_sys_modules_main_name = self.user_module.__name__
         self._orig_sys_modules_main_mod = sys.modules.get(self.user_module.__name__)
 
     def restore_sys_module_state(self):
         """Restore the state of the sys module."""
         try:
             for k, v in self._orig_sys_module_state.items():
                 setattr(sys, k, v)
         except AttributeError:
             pass
         # Reset what what done in self.init_sys_modules
         if self._orig_sys_modules_main_mod is not None:
             sys.modules[self._orig_sys_modules_main_name] = self._orig_sys_modules_main_mod
 
     #-------------------------------------------------------------------------
     # Things related to the banner
     #-------------------------------------------------------------------------
 
     @property
     def banner(self):
         banner = self.banner1
         if self.profile and self.profile != 'default':
             banner += '\nIPython profile: %s\n' % self.profile
         if self.banner2:
             banner += '\n' + self.banner2
         return banner
 
     def show_banner(self, banner=None):
         if banner is None:
             banner = self.banner
         sys.stdout.write(banner)
 
     #-------------------------------------------------------------------------
     # Things related to hooks
     #-------------------------------------------------------------------------
 
     def init_hooks(self):
         # hooks holds pointers used for user-side customizations
         self.hooks = Struct()
 
         self.strdispatchers = {}
 
         # Set all default hooks, defined in the IPython.hooks module.
         hooks = IPython.core.hooks
         for hook_name in hooks.__all__:
             # default hooks have priority 100, i.e. low; user hooks should have
             # 0-100 priority
             self.set_hook(hook_name,getattr(hooks,hook_name), 100, _warn_deprecated=False)
 
         if self.display_page:
             self.set_hook('show_in_pager', page.as_hook(page.display_page), 90)
 
     def set_hook(self,name,hook, priority=50, str_key=None, re_key=None,
                  _warn_deprecated=True):
         """set_hook(name,hook) -> sets an internal IPython hook.
 
         IPython exposes some of its internal API as user-modifiable hooks.  By
         adding your function to one of these hooks, you can modify IPython's
         behavior to call at runtime your own routines."""
 
         # At some point in the future, this should validate the hook before it
         # accepts it.  Probably at least check that the hook takes the number
         # of args it's supposed to.
 
         f = types.MethodType(hook,self)
 
         # check if the hook is for strdispatcher first
         if str_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_s(str_key, f, priority )
             self.strdispatchers[name] = sdp
             return
         if re_key is not None:
             sdp = self.strdispatchers.get(name, StrDispatch())
             sdp.add_re(re.compile(re_key), f, priority )
             self.strdispatchers[name] = sdp
             return
 
         dp = getattr(self.hooks, name, None)
         if name not in IPython.core.hooks.__all__:
             print("Warning! Hook '%s' is not one of %s" % \
                   (name, IPython.core.hooks.__all__ ))
 
         if _warn_deprecated and (name in IPython.core.hooks.deprecated):
             alternative = IPython.core.hooks.deprecated[name]
             warn("Hook {} is deprecated. Use {} instead.".format(name, alternative), stacklevel=2)
 
         if not dp:
             dp = IPython.core.hooks.CommandChainDispatcher()
 
         try:
             dp.add(f,priority)
         except AttributeError:
             # it was not commandchain, plain old func - replace
             dp = f
 
         setattr(self.hooks,name, dp)
 
     #-------------------------------------------------------------------------
     # Things related to events
     #-------------------------------------------------------------------------
 
     def init_events(self):
         self.events = EventManager(self, available_events)
 
         self.events.register("pre_execute", self._clear_warning_registry)
 
     def register_post_execute(self, func):
         """DEPRECATED: Use ip.events.register('post_run_cell', func)
 
         Register a function for calling after code execution.
         """
         warn("ip.register_post_execute is deprecated, use "
              "ip.events.register('post_run_cell', func) instead.", stacklevel=2)
         self.events.register('post_run_cell', func)
 
     def _clear_warning_registry(self):
         # clear the warning registry, so that different code blocks with
         # overlapping line number ranges don't cause spurious suppression of
         # warnings (see gh-6611 for details)
         if "__warningregistry__" in self.user_global_ns:
             del self.user_global_ns["__warningregistry__"]
 
     #-------------------------------------------------------------------------
     # Things related to the "main" module
     #-------------------------------------------------------------------------
 
     def new_main_mod(self, filename, modname):
         """Return a new 'main' module object for user code execution.
 
         ``filename`` should be the path of the script which will be run in the
         module. Requests with the same filename will get the same module, with
         its namespace cleared.
 
         ``modname`` should be the module name - normally either '__main__' or
         the basename of the file without the extension.
 
         When scripts are executed via %run, we must keep a reference to their
         __main__ module around so that Python doesn't
         clear it, rendering references to module globals useless.
 
         This method keeps said reference in a private dict, keyed by the
         absolute path of the script. This way, for multiple executions of the
         same script we only keep one copy of the namespace (the last one),
         thus preventing memory leaks from old references while allowing the
         objects from the last execution to be accessible.
         """
         filename = os.path.abspath(filename)
         try:
             main_mod = self._main_mod_cache[filename]
         except KeyError:
             main_mod = self._main_mod_cache[filename] = types.ModuleType(
                         modname,
                         doc="Module created for script run in IPython")
         else:
             main_mod.__dict__.clear()
             main_mod.__name__ = modname
 
         main_mod.__file__ = filename
         # It seems pydoc (and perhaps others) needs any module instance to
         # implement a __nonzero__ method
         main_mod.__nonzero__ = lambda : True
 
         return main_mod
 
     def clear_main_mod_cache(self):
         """Clear the cache of main modules.
 
         Mainly for use by utilities like %reset.
 
         Examples
         --------
         In [15]: import IPython
 
         In [16]: m = _ip.new_main_mod(IPython.__file__, 'IPython')
 
         In [17]: len(_ip._main_mod_cache) > 0
         Out[17]: True
 
         In [18]: _ip.clear_main_mod_cache()
 
         In [19]: len(_ip._main_mod_cache) == 0
         Out[19]: True
         """
         self._main_mod_cache.clear()
 
     #-------------------------------------------------------------------------
     # Things related to debugging
     #-------------------------------------------------------------------------
 
     def init_pdb(self):
         # Set calling of pdb on exceptions
         # self.call_pdb is a property
         self.call_pdb = self.pdb
 
     def _get_call_pdb(self):
         return self._call_pdb
 
     def _set_call_pdb(self,val):
 
         if val not in (0,1,False,True):
             raise ValueError('new call_pdb value must be boolean')
 
         # store value in instance
         self._call_pdb = val
 
         # notify the actual exception handlers
         self.InteractiveTB.call_pdb = val
 
     call_pdb = property(_get_call_pdb,_set_call_pdb,None,
                         'Control auto-activation of pdb at exceptions')
 
     def debugger(self,force=False):
         """Call the pdb debugger.
 
         Keywords:
 
           - force(False): by default, this routine checks the instance call_pdb
             flag and does not actually invoke the debugger if the flag is false.
             The 'force' option forces the debugger to activate even if the flag
             is false.
         """
 
         if not (force or self.call_pdb):
             return
 
         if not hasattr(sys,'last_traceback'):
             error('No traceback has been produced, nothing to debug.')
             return
 
         self.InteractiveTB.debugger(force=True)
 
     #-------------------------------------------------------------------------
     # Things related to IPython's various namespaces
     #-------------------------------------------------------------------------
     default_user_namespaces = True
 
     def init_create_namespaces(self, user_module=None, user_ns=None):
         # Create the namespace where the user will operate.  user_ns is
         # normally the only one used, and it is passed to the exec calls as
         # the locals argument.  But we do carry a user_global_ns namespace
         # given as the exec 'globals' argument,  This is useful in embedding
         # situations where the ipython shell opens in a context where the
         # distinction between locals and globals is meaningful.  For
         # non-embedded contexts, it is just the same object as the user_ns dict.
 
         # FIXME. For some strange reason, __builtins__ is showing up at user
         # level as a dict instead of a module. This is a manual fix, but I
         # should really track down where the problem is coming from. Alex
         # Schmolck reported this problem first.
 
         # A useful post by Alex Martelli on this topic:
         # Re: inconsistent value from __builtins__
         # Von: Alex Martelli <[e-mail]>
         # Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
         # Gruppen: comp.lang.python
 
         # Michael Hohn <[e-mail]> wrote:
         # > >>> print type(builtin_check.get_global_binding('__builtins__'))
         # > <type 'dict'>
         # > >>> print type(__builtins__)
         # > <type 'module'>
         # > Is this difference in return value intentional?
 
         # Well, it's documented that '__builtins__' can be either a dictionary
         # or a module, and it's been that way for a long time. Whether it's
         # intentional (or sensible), I don't know. In any case, the idea is
         # that if you need to access the built-in namespace directly, you
         # should start with "import __builtin__" (note, no 's') which will
         # definitely give you a module. Yeah, it's somewhat confusing:-(.
 
         # These routines return a properly built module and dict as needed by
         # the rest of the code, and can also be used by extension writers to
         # generate properly initialized namespaces.
         if (user_ns is not None) or (user_module is not None):
             self.default_user_namespaces = False
         self.user_module, self.user_ns = self.prepare_user_module(user_module, user_ns)
 
         # A record of hidden variables we have added to the user namespace, so
         # we can list later only variables defined in actual interactive use.
         self.user_ns_hidden = {}
 
         # Now that FakeModule produces a real module, we've run into a nasty
         # problem: after script execution (via %run), the module where the user
         # code ran is deleted.  Now that this object is a true module (needed
         # so doctest and other tools work correctly), the Python module
         # teardown mechanism runs over it, and sets to None every variable
         # present in that module.  Top-level references to objects from the
         # script survive, because the user_ns is updated with them.  However,
         # calling functions defined in the script that use other things from
         # the script will fail, because the function's closure had references
         # to the original objects, which are now all None.  So we must protect
         # these modules from deletion by keeping a cache.
         #
         # To avoid keeping stale modules around (we only need the one from the
         # last run), we use a dict keyed with the full path to the script, so
         # only the last version of the module is held in the cache.  Note,
         # however, that we must cache the module *namespace contents* (their
         # __dict__).  Because if we try to cache the actual modules, old ones
         # (uncached) could be destroyed while still holding references (such as
         # those held by GUI objects that tend to be long-lived)>
         #
         # The %reset command will flush this cache.  See the cache_main_mod()
         # and clear_main_mod_cache() methods for details on use.
 
         # This is the cache used for 'main' namespaces
         self._main_mod_cache = {}
 
         # A table holding all the namespaces IPython deals with, so that
         # introspection facilities can search easily.
         self.ns_table = {'user_global':self.user_module.__dict__,
                          'user_local':self.user_ns,
                          'builtin':builtin_mod.__dict__
                          }
 
     @property
     def user_global_ns(self):
         return self.user_module.__dict__
 
     def prepare_user_module(self, user_module=None, user_ns=None):
         """Prepare the module and namespace in which user code will be run.
 
         When IPython is started normally, both parameters are None: a new module
         is created automatically, and its __dict__ used as the namespace.
 
         If only user_module is provided, its __dict__ is used as the namespace.
         If only user_ns is provided, a dummy module is created, and user_ns
         becomes the global namespace. If both are provided (as they may be
         when embedding), user_ns is the local namespace, and user_module
         provides the global namespace.
 
         Parameters
         ----------
         user_module : module, optional
             The current user module in which IPython is being run. If None,
             a clean module will be created.
         user_ns : dict, optional
             A namespace in which to run interactive commands.
 
         Returns
         -------
         A tuple of user_module and user_ns, each properly initialised.
         """
         if user_module is None and user_ns is not None:
             user_ns.setdefault("__name__", "__main__")
             user_module = DummyMod()
             user_module.__dict__ = user_ns
 
         if user_module is None:
             user_module = types.ModuleType("__main__",
                 doc="Automatically created module for IPython interactive environment")
 
         # We must ensure that __builtin__ (without the final 's') is always
         # available and pointing to the __builtin__ *module*.  For more details:
         # http://mail.python.org/pipermail/python-dev/2001-April/014068.html
         user_module.__dict__.setdefault('__builtin__', builtin_mod)
         user_module.__dict__.setdefault('__builtins__', builtin_mod)
 
         if user_ns is None:
             user_ns = user_module.__dict__
 
         return user_module, user_ns
 
     def init_sys_modules(self):
         # We need to insert into sys.modules something that looks like a
         # module but which accesses the IPython namespace, for shelve and
         # pickle to work interactively. Normally they rely on getting
         # everything out of __main__, but for embedding purposes each IPython
         # instance has its own private namespace, so we can't go shoving
         # everything into __main__.
 
         # note, however, that we should only do this for non-embedded
         # ipythons, which really mimic the __main__.__dict__ with their own
         # namespace.  Embedded instances, on the other hand, should not do
         # this because they need to manage the user local/global namespaces
         # only, but they live within a 'normal' __main__ (meaning, they
         # shouldn't overtake the execution environment of the script they're
         # embedded in).
 
         # This is overridden in the InteractiveShellEmbed subclass to a no-op.
         main_name = self.user_module.__name__
         sys.modules[main_name] = self.user_module
 
     def init_user_ns(self):
         """Initialize all user-visible namespaces to their minimum defaults.
 
         Certain history lists are also initialized here, as they effectively
         act as user namespaces.
 
         Notes
         -----
         All data structures here are only filled in, they are NOT reset by this
         method.  If they were not empty before, data will simply be added to
         them.
         """
         # This function works in two parts: first we put a few things in
         # user_ns, and we sync that contents into user_ns_hidden so that these
         # initial variables aren't shown by %who.  After the sync, we add the
         # rest of what we *do* want the user to see with %who even on a new
         # session (probably nothing, so they really only see their own stuff)
 
         # The user dict must *always* have a __builtin__ reference to the
         # Python standard __builtin__ namespace,  which must be imported.
         # This is so that certain operations in prompt evaluation can be
         # reliably executed with builtins.  Note that we can NOT use
         # __builtins__ (note the 's'),  because that can either be a dict or a
         # module, and can even mutate at runtime, depending on the context
         # (Python makes no guarantees on it).  In contrast, __builtin__ is
         # always a module object, though it must be explicitly imported.
 
         # For more details:
         # http://mail.python.org/pipermail/python-dev/2001-April/014068.html
         ns = {}
 
         # make global variables for user access to the histories
         ns['_ih'] = self.history_manager.input_hist_parsed
         ns['_oh'] = self.history_manager.output_hist
         ns['_dh'] = self.history_manager.dir_hist
 
         # user aliases to input and output histories.  These shouldn't show up
         # in %who, as they can have very large reprs.
         ns['In']  = self.history_manager.input_hist_parsed
         ns['Out'] = self.history_manager.output_hist
 
         # Store myself as the public api!!!
         ns['get_ipython'] = self.get_ipython
 
         ns['exit'] = self.exiter
         ns['quit'] = self.exiter
 
         # Sync what we've added so far to user_ns_hidden so these aren't seen
         # by %who
         self.user_ns_hidden.update(ns)
 
         # Anything put into ns now would show up in %who.  Think twice before
         # putting anything here, as we really want %who to show the user their
         # stuff, not our variables.
 
         # Finally, update the real user's namespace
         self.user_ns.update(ns)
 
     @property
     def all_ns_refs(self):
         """Get a list of references to all the namespace dictionaries in which
         IPython might store a user-created object.
 
         Note that this does not include the displayhook, which also caches
         objects from the output."""
         return [self.user_ns, self.user_global_ns, self.user_ns_hidden] + \
                [m.__dict__ for m in self._main_mod_cache.values()]
 
     def reset(self, new_session=True, aggressive=False):
         """Clear all internal namespaces, and attempt to release references to
         user objects.
 
         If new_session is True, a new history session will be opened.
         """
         # Clear histories
         self.history_manager.reset(new_session)
         # Reset counter used to index all histories
         if new_session:
             self.execution_count = 1
 
         # Reset last execution result
         self.last_execution_succeeded = True
         self.last_execution_result = None
 
         # Flush cached output items
         if self.displayhook.do_full_cache:
             self.displayhook.flush()
 
         # The main execution namespaces must be cleared very carefully,
         # skipping the deletion of the builtin-related keys, because doing so
         # would cause errors in many object's __del__ methods.
         if self.user_ns is not self.user_global_ns:
             self.user_ns.clear()
         ns = self.user_global_ns
         drop_keys = set(ns.keys())
         drop_keys.discard('__builtin__')
         drop_keys.discard('__builtins__')
         drop_keys.discard('__name__')
         for k in drop_keys:
             del ns[k]
 
         self.user_ns_hidden.clear()
 
         # Restore the user namespaces to minimal usability
         self.init_user_ns()
         if aggressive and not hasattr(self, "_sys_modules_keys"):
             print("Cannot restore sys.module, no snapshot")
         elif aggressive:
             print("culling sys module...")
             current_keys = set(sys.modules.keys())
             for k in current_keys - self._sys_modules_keys:
                 if k.startswith("multiprocessing"):
                     continue
                 del sys.modules[k]
 
         # Restore the default and user aliases
         self.alias_manager.clear_aliases()
         self.alias_manager.init_aliases()
 
         # Now define aliases that only make sense on the terminal, because they
         # need direct access to the console in a way that we can't emulate in
         # GUI or web frontend
         if os.name == 'posix':
             for cmd in ('clear', 'more', 'less', 'man'):
                 if cmd not in self.magics_manager.magics['line']:
                     self.alias_manager.soft_define_alias(cmd, cmd)
 
         # Flush the private list of module references kept for script
         # execution protection
         self.clear_main_mod_cache()
 
     def del_var(self, varname, by_name=False):
         """Delete a variable from the various namespaces, so that, as
         far as possible, we're not keeping any hidden references to it.
 
         Parameters
         ----------
         varname : str
             The name of the variable to delete.
         by_name : bool
             If True, delete variables with the given name in each
             namespace. If False (default), find the variable in the user
             namespace, and delete references to it.
         """
         if varname in ('__builtin__', '__builtins__'):
             raise ValueError("Refusing to delete %s" % varname)
 
         ns_refs = self.all_ns_refs
 
         if by_name:                    # Delete by name
             for ns in ns_refs:
                 try:
                     del ns[varname]
                 except KeyError:
                     pass
         else:                         # Delete by object
             try:
                 obj = self.user_ns[varname]
             except KeyError as e:
                 raise NameError("name '%s' is not defined" % varname) from e
             # Also check in output history
             ns_refs.append(self.history_manager.output_hist)
             for ns in ns_refs:
                 to_delete = [n for n, o in ns.items() if o is obj]
                 for name in to_delete:
                     del ns[name]
 
             # Ensure it is removed from the last execution result
             if self.last_execution_result.result is obj:
                 self.last_execution_result = None
 
             # displayhook keeps extra references, but not in a dictionary
             for name in ('_', '__', '___'):
                 if getattr(self.displayhook, name) is obj:
                     setattr(self.displayhook, name, None)
 
     def reset_selective(self, regex=None):
         """Clear selective variables from internal namespaces based on a
         specified regular expression.
 
         Parameters
         ----------
         regex : string or compiled pattern, optional
             A regular expression pattern that will be used in searching
             variable names in the users namespaces.
         """
         if regex is not None:
             try:
                 m = re.compile(regex)
             except TypeError as e:
                 raise TypeError('regex must be a string or compiled pattern') from e
             # Search for keys in each namespace that match the given regex
             # If a match is found, delete the key/value pair.
             for ns in self.all_ns_refs:
                 for var in ns:
                     if m.search(var):
                         del ns[var]
 
     def push(self, variables, interactive=True):
         """Inject a group of variables into the IPython user namespace.
 
         Parameters
         ----------
         variables : dict, str or list/tuple of str
             The variables to inject into the user's namespace.  If a dict, a
             simple update is done.  If a str, the string is assumed to have
             variable names separated by spaces.  A list/tuple of str can also
             be used to give the variable names.  If just the variable names are
             give (list/tuple/str) then the variable values looked up in the
             callers frame.
         interactive : bool
             If True (default), the variables will be listed with the ``who``
             magic.
         """
         vdict = None
 
         # We need a dict of name/value pairs to do namespace updates.
         if isinstance(variables, dict):
             vdict = variables
         elif isinstance(variables, (str, list, tuple)):
             if isinstance(variables, str):
                 vlist = variables.split()
             else:
                 vlist = variables
             vdict = {}
             cf = sys._getframe(1)
             for name in vlist:
                 try:
                     vdict[name] = eval(name, cf.f_globals, cf.f_locals)
                 except:
                     print('Could not get variable %s from %s' %
                            (name,cf.f_code.co_name))
         else:
             raise ValueError('variables must be a dict/str/list/tuple')
 
         # Propagate variables to user namespace
         self.user_ns.update(vdict)
 
         # And configure interactive visibility
         user_ns_hidden = self.user_ns_hidden
         if interactive:
             for name in vdict:
                 user_ns_hidden.pop(name, None)
         else:
             user_ns_hidden.update(vdict)
 
     def drop_by_id(self, variables):
         """Remove a dict of variables from the user namespace, if they are the
         same as the values in the dictionary.
 
         This is intended for use by extensions: variables that they've added can
         be taken back out if they are unloaded, without removing any that the
         user has overwritten.
 
         Parameters
         ----------
         variables : dict
             A dictionary mapping object names (as strings) to the objects.
         """
         for name, obj in variables.items():
             if name in self.user_ns and self.user_ns[name] is obj:
                 del self.user_ns[name]
                 self.user_ns_hidden.pop(name, None)
 
     #-------------------------------------------------------------------------
     # Things related to object introspection
     #-------------------------------------------------------------------------
 
     def _ofind(self, oname, namespaces=None):
         """Find an object in the available namespaces.
 
         self._ofind(oname) -> dict with keys: found,obj,ospace,ismagic
 
         Has special code to detect magic functions.
         """
         oname = oname.strip()
         if not oname.startswith(ESC_MAGIC) and \
                 not oname.startswith(ESC_MAGIC2) and \
                 not all(a.isidentifier() for a in oname.split(".")):
             return {'found': False}
 
         if namespaces is None:
             # Namespaces to search in:
             # Put them in a list. The order is important so that we
             # find things in the same order that Python finds them.
             namespaces = [ ('Interactive', self.user_ns),
                            ('Interactive (global)', self.user_global_ns),
                            ('Python builtin', builtin_mod.__dict__),
                            ]
 
         ismagic = False
         isalias = False
         found = False
         ospace = None
         parent = None
         obj = None
 
 
         # Look for the given name by splitting it in parts.  If the head is
         # found, then we look for all the remaining parts as members, and only
         # declare success if we can find them all.
         oname_parts = oname.split('.')
         oname_head, oname_rest = oname_parts[0],oname_parts[1:]
         for nsname,ns in namespaces:
             try:
                 obj = ns[oname_head]
             except KeyError:
                 continue
             else:
                 for idx, part in enumerate(oname_rest):
                     try:
                         parent = obj
                         # The last part is looked up in a special way to avoid
                         # descriptor invocation as it may raise or have side
                         # effects.
                         if idx == len(oname_rest) - 1:
                             obj = self._getattr_property(obj, part)
                         else:
                             obj = getattr(obj, part)
                     except:
                         # Blanket except b/c some badly implemented objects
                         # allow __getattr__ to raise exceptions other than
                         # AttributeError, which then crashes IPython.
                         break
                 else:
                     # If we finish the for loop (no break), we got all members
                     found = True
                     ospace = nsname
                     break  # namespace loop
 
         # Try to see if it's magic
         if not found:
             obj = None
             if oname.startswith(ESC_MAGIC2):
                 oname = oname.lstrip(ESC_MAGIC2)
                 obj = self.find_cell_magic(oname)
             elif oname.startswith(ESC_MAGIC):
                 oname = oname.lstrip(ESC_MAGIC)
                 obj = self.find_line_magic(oname)
             else:
                 # search without prefix, so run? will find %run?
                 obj = self.find_line_magic(oname)
                 if obj is None:
                     obj = self.find_cell_magic(oname)
             if obj is not None:
                 found = True
                 ospace = 'IPython internal'
                 ismagic = True
                 isalias = isinstance(obj, Alias)
 
         # Last try: special-case some literals like '', [], {}, etc:
         if not found and oname_head in ["''",'""','[]','{}','()']:
             obj = eval(oname_head)
             found = True
             ospace = 'Interactive'
 
         return {
                 'obj':obj,
                 'found':found,
                 'parent':parent,
                 'ismagic':ismagic,
                 'isalias':isalias,
                 'namespace':ospace
                }
 
     @staticmethod
     def _getattr_property(obj, attrname):
         """Property-aware getattr to use in object finding.
 
         If attrname represents a property, return it unevaluated (in case it has
         side effects or raises an error.
 
         """
         if not isinstance(obj, type):
             try:
                 # `getattr(type(obj), attrname)` is not guaranteed to return
                 # `obj`, but does so for property:
                 #
                 # property.__get__(self, None, cls) -> self
                 #
                 # The universal alternative is to traverse the mro manually
                 # searching for attrname in class dicts.
                 attr = getattr(type(obj), attrname)
             except AttributeError:
                 pass
             else:
                 # This relies on the fact that data descriptors (with both
                 # __get__ & __set__ magic methods) take precedence over
                 # instance-level attributes:
                 #
                 #    class A(object):
                 #        @property
                 #        def foobar(self): return 123
                 #    a = A()
                 #    a.__dict__['foobar'] = 345
                 #    a.foobar  # == 123
                 #
                 # So, a property may be returned right away.
                 if isinstance(attr, property):
                     return attr
 
         # Nothing helped, fall back.
         return getattr(obj, attrname)
 
     def _object_find(self, oname, namespaces=None):
         """Find an object and return a struct with info about it."""
         return Struct(self._ofind(oname, namespaces))
 
     def _inspect(self, meth, oname, namespaces=None, **kw):
         """Generic interface to the inspector system.
 
         This function is meant to be called by pdef, pdoc & friends.
         """
         info = self._object_find(oname, namespaces)
         docformat = sphinxify if self.sphinxify_docstring else None
         if info.found:
             pmethod = getattr(self.inspector, meth)
             # TODO: only apply format_screen to the plain/text repr of the mime
             # bundle.
             formatter = format_screen if info.ismagic else docformat
             if meth == 'pdoc':
                 pmethod(info.obj, oname, formatter)
             elif meth == 'pinfo':
                 pmethod(
                     info.obj,
                     oname,
                     formatter,
                     info,
                     enable_html_pager=self.enable_html_pager,
                     **kw
                 )
             else:
                 pmethod(info.obj, oname)
         else:
             print('Object `%s` not found.' % oname)
             return 'not found'  # so callers can take other action
 
     def object_inspect(self, oname, detail_level=0):
         """Get object info about oname"""
         with self.builtin_trap:
             info = self._object_find(oname)
             if info.found:
                 return self.inspector.info(info.obj, oname, info=info,
                             detail_level=detail_level
                 )
             else:
                 return oinspect.object_info(name=oname, found=False)
 
     def object_inspect_text(self, oname, detail_level=0):
         """Get object info as formatted text"""
         return self.object_inspect_mime(oname, detail_level)['text/plain']
 
     def object_inspect_mime(self, oname, detail_level=0):
         """Get object info as a mimebundle of formatted representations.
 
         A mimebundle is a dictionary, keyed by mime-type.
         It must always have the key `'text/plain'`.
         """
         with self.builtin_trap:
             info = self._object_find(oname)
             if info.found:
                 return self.inspector._get_info(info.obj, oname, info=info,
                             detail_level=detail_level
                 )
             else:
                 raise KeyError(oname)
 
     #-------------------------------------------------------------------------
     # Things related to history management
     #-------------------------------------------------------------------------
 
     def init_history(self):
         """Sets up the command history, and starts regular autosaves."""
         self.history_manager = HistoryManager(shell=self, parent=self)
         self.configurables.append(self.history_manager)
 
     #-------------------------------------------------------------------------
     # Things related to exception handling and tracebacks (not debugging)
     #-------------------------------------------------------------------------
 
     debugger_cls = Pdb
 
     def init_traceback_handlers(self, custom_exceptions):
         # Syntax error handler.
         self.SyntaxTB = ultratb.SyntaxTB(color_scheme='NoColor', parent=self)
 
         # The interactive one is initialized with an offset, meaning we always
         # want to remove the topmost item in the traceback, which is our own
         # internal code. Valid modes: ['Plain','Context','Verbose','Minimal']
         self.InteractiveTB = ultratb.AutoFormattedTB(mode = 'Plain',
                                                      color_scheme='NoColor',
                                                      tb_offset = 1,
                                    check_cache=check_linecache_ipython,
                                    debugger_cls=self.debugger_cls, parent=self)
 
         # The instance will store a pointer to the system-wide exception hook,
         # so that runtime code (such as magics) can access it.  This is because
         # during the read-eval loop, it may get temporarily overwritten.
         self.sys_excepthook = sys.excepthook
 
         # and add any custom exception handlers the user may have specified
         self.set_custom_exc(*custom_exceptions)
 
         # Set the exception mode
         self.InteractiveTB.set_mode(mode=self.xmode)
 
     def set_custom_exc(self, exc_tuple, handler):
         """set_custom_exc(exc_tuple, handler)
 
         Set a custom exception handler, which will be called if any of the
         exceptions in exc_tuple occur in the mainloop (specifically, in the
         run_code() method).
 
         Parameters
         ----------
 
         exc_tuple : tuple of exception classes
             A *tuple* of exception classes, for which to call the defined
             handler.  It is very important that you use a tuple, and NOT A
             LIST here, because of the way Python's except statement works.  If
             you only want to trap a single exception, use a singleton tuple::
 
                 exc_tuple == (MyCustomException,)
 
         handler : callable
             handler must have the following signature::
 
                 def my_handler(self, etype, value, tb, tb_offset=None):
                     ...
                     return structured_traceback
 
             Your handler must return a structured traceback (a list of strings),
             or None.
 
             This will be made into an instance method (via types.MethodType)
             of IPython itself, and it will be called if any of the exceptions
             listed in the exc_tuple are caught. If the handler is None, an
             internal basic one is used, which just prints basic info.
 
             To protect IPython from crashes, if your handler ever raises an
             exception or returns an invalid result, it will be immediately
             disabled.
 
         Notes
         -----
 
         WARNING: by putting in your own exception handler into IPython's main
         execution loop, you run a very good chance of nasty crashes.  This
         facility should only be used if you really know what you are doing.
         """
 
         if not isinstance(exc_tuple, tuple):
             raise TypeError("The custom exceptions must be given as a tuple.")
 
         def dummy_handler(self, etype, value, tb, tb_offset=None):
             print('*** Simple custom exception handler ***')
             print('Exception type :', etype)
             print('Exception value:', value)
             print('Traceback      :', tb)
 
         def validate_stb(stb):
             """validate structured traceback return type
 
             return type of CustomTB *should* be a list of strings, but allow
             single strings or None, which are harmless.
 
             This function will *always* return a list of strings,
             and will raise a TypeError if stb is inappropriate.
             """
             msg = "CustomTB must return list of strings, not %r" % stb
             if stb is None:
                 return []
             elif isinstance(stb, str):
                 return [stb]
             elif not isinstance(stb, list):
                 raise TypeError(msg)
             # it's a list
             for line in stb:
                 # check every element
                 if not isinstance(line, str):
                     raise TypeError(msg)
             return stb
 
         if handler is None:
             wrapped = dummy_handler
         else:
             def wrapped(self,etype,value,tb,tb_offset=None):
                 """wrap CustomTB handler, to protect IPython from user code
 
                 This makes it harder (but not impossible) for custom exception
                 handlers to crash IPython.
                 """
                 try:
                     stb = handler(self,etype,value,tb,tb_offset=tb_offset)
                     return validate_stb(stb)
                 except:
                     # clear custom handler immediately
                     self.set_custom_exc((), None)
                     print("Custom TB Handler failed, unregistering", file=sys.stderr)
                     # show the exception in handler first
                     stb = self.InteractiveTB.structured_traceback(*sys.exc_info())
                     print(self.InteractiveTB.stb2text(stb))
                     print("The original exception:")
                     stb = self.InteractiveTB.structured_traceback(
                                             (etype,value,tb), tb_offset=tb_offset
                     )
                 return stb
 
         self.CustomTB = types.MethodType(wrapped,self)
         self.custom_exceptions = exc_tuple
 
     def excepthook(self, etype, value, tb):
         """One more defense for GUI apps that call sys.excepthook.
 
         GUI frameworks like wxPython trap exceptions and call
         sys.excepthook themselves.  I guess this is a feature that
         enables them to keep running after exceptions that would
         otherwise kill their mainloop. This is a bother for IPython
         which expects to catch all of the program exceptions with a try:
         except: statement.
 
         Normally, IPython sets sys.excepthook to a CrashHandler instance, so if
         any app directly invokes sys.excepthook, it will look to the user like
         IPython crashed.  In order to work around this, we can disable the
         CrashHandler and replace it with this excepthook instead, which prints a
         regular traceback using our InteractiveTB.  In this fashion, apps which
         call sys.excepthook will generate a regular-looking exception from
         IPython, and the CrashHandler will only be triggered by real IPython
         crashes.
 
         This hook should be used sparingly, only in places which are not likely
         to be true IPython errors.
         """
         self.showtraceback((etype, value, tb), tb_offset=0)
 
     def _get_exc_info(self, exc_tuple=None):
         """get exc_info from a given tuple, sys.exc_info() or sys.last_type etc.
 
         Ensures sys.last_type,value,traceback hold the exc_info we found,
         from whichever source.
 
         raises ValueError if none of these contain any information
         """
         if exc_tuple is None:
             etype, value, tb = sys.exc_info()
         else:
             etype, value, tb = exc_tuple
 
         if etype is None:
             if hasattr(sys, 'last_type'):
                 etype, value, tb = sys.last_type, sys.last_value, \
                                    sys.last_traceback
 
         if etype is None:
             raise ValueError("No exception to find")
 
         # Now store the exception info in sys.last_type etc.
         # WARNING: these variables are somewhat deprecated and not
         # necessarily safe to use in a threaded environment, but tools
         # like pdb depend on their existence, so let's set them.  If we
         # find problems in the field, we'll need to revisit their use.
         sys.last_type = etype
         sys.last_value = value
         sys.last_traceback = tb
 
         return etype, value, tb
 
     def show_usage_error(self, exc):
         """Show a short message for UsageErrors
 
         These are special exceptions that shouldn't show a traceback.
         """
         print("UsageError: %s" % exc, file=sys.stderr)
 
     def get_exception_only(self, exc_tuple=None):
         """
         Return as a string (ending with a newline) the exception that
         just occurred, without any traceback.
         """
         etype, value, tb = self._get_exc_info(exc_tuple)
         msg = traceback.format_exception_only(etype, value)
         return ''.join(msg)
 
     def showtraceback(self, exc_tuple=None, filename=None, tb_offset=None,
                       exception_only=False, running_compiled_code=False):
         """Display the exception that just occurred.
 
         If nothing is known about the exception, this is the method which
         should be used throughout the code for presenting user tracebacks,
         rather than directly invoking the InteractiveTB object.
 
         A specific showsyntaxerror() also exists, but this method can take
         care of calling it if needed, so unless you are explicitly catching a
         SyntaxError exception, don't try to analyze the stack manually and
         simply call this method."""
 
         try:
             try:
                 etype, value, tb = self._get_exc_info(exc_tuple)
             except ValueError:
                 print('No traceback available to show.', file=sys.stderr)
                 return
 
             if issubclass(etype, SyntaxError):
                 # Though this won't be called by syntax errors in the input
                 # line, there may be SyntaxError cases with imported code.
                 self.showsyntaxerror(filename, running_compiled_code)
             elif etype is UsageError:
                 self.show_usage_error(value)
             else:
                 if exception_only:
                     stb = ['An exception has occurred, use %tb to see '
                            'the full traceback.\n']
                     stb.extend(self.InteractiveTB.get_exception_only(etype,
                                                                      value))
                 else:
                     try:
                         # Exception classes can customise their traceback - we
                         # use this in IPython.parallel for exceptions occurring
                         # in the engines. This should return a list of strings.
                         stb = value._render_traceback_()
                     except Exception:
                         stb = self.InteractiveTB.structured_traceback(etype,
                                             value, tb, tb_offset=tb_offset)
 
                     self._showtraceback(etype, value, stb)
                     if self.call_pdb:
                         # drop into debugger
                         self.debugger(force=True)
                     return
 
                 # Actually show the traceback
                 self._showtraceback(etype, value, stb)
 
         except KeyboardInterrupt:
             print('\n' + self.get_exception_only(), file=sys.stderr)
 
     def _showtraceback(self, etype, evalue, stb: str):
         """Actually show a traceback.
 
         Subclasses may override this method to put the traceback on a different
         place, like a side channel.
         """
         val = self.InteractiveTB.stb2text(stb)
         try:
             print(val)
         except UnicodeEncodeError:
             print(val.encode("utf-8", "backslashreplace").decode())
 
     def showsyntaxerror(self, filename=None, running_compiled_code=False):
         """Display the syntax error that just occurred.
 
         This doesn't display a stack trace because there isn't one.
 
         If a filename is given, it is stuffed in the exception instead
         of what was there before (because Python's parser always uses
         "<string>" when reading from a string).
 
         If the syntax error occurred when running a compiled code (i.e. running_compile_code=True),
         longer stack trace will be displayed.
          """
         etype, value, last_traceback = self._get_exc_info()
 
         if filename and issubclass(etype, SyntaxError):
             try:
                 value.filename = filename
             except:
                 # Not the format we expect; leave it alone
                 pass
 
         # If the error occurred when executing compiled code, we should provide full stacktrace.
         elist = traceback.extract_tb(last_traceback) if running_compiled_code else []
         stb = self.SyntaxTB.structured_traceback(etype, value, elist)
         self._showtraceback(etype, value, stb)
 
     # This is overridden in TerminalInteractiveShell to show a message about
     # the %paste magic.
     def showindentationerror(self):
         """Called by _run_cell when there's an IndentationError in code entered
         at the prompt.
 
         This is overridden in TerminalInteractiveShell to show a message about
         the %paste magic."""
         self.showsyntaxerror()
 
     #-------------------------------------------------------------------------
     # Things related to readline
     #-------------------------------------------------------------------------
 
     def init_readline(self):
         """DEPRECATED
 
         Moved to terminal subclass, here only to simplify the init logic."""
         # Set a number of methods that depend on readline to be no-op
         warnings.warn('`init_readline` is no-op since IPython 5.0 and is Deprecated',
                 DeprecationWarning, stacklevel=2)
         self.set_custom_completer = no_op
 
     @skip_doctest
     def set_next_input(self, s, replace=False):
         """ Sets the 'default' input string for the next command line.
 
         Example::
 
             In [1]: _ip.set_next_input("Hello Word")
             In [2]: Hello Word_  # cursor is here
         """
         self.rl_next_input = s
 
     def _indent_current_str(self):
         """return the current level of indentation as a string"""
         return self.input_splitter.get_indent_spaces() * ' '
 
     #-------------------------------------------------------------------------
     # Things related to text completion
     #-------------------------------------------------------------------------
 
     def init_completer(self):
         """Initialize the completion machinery.
 
         This creates completion machinery that can be used by client code,
         either interactively in-process (typically triggered by the readline
         library), programmatically (such as in test suites) or out-of-process
         (typically over the network by remote frontends).
         """
         from IPython.core.completer import IPCompleter
         from IPython.core.completerlib import (module_completer,
                 magic_run_completer, cd_completer, reset_completer)
 
         self.Completer = IPCompleter(shell=self,
                                      namespace=self.user_ns,
                                      global_namespace=self.user_global_ns,
                                      parent=self,
                                      )
         self.configurables.append(self.Completer)
 
         # Add custom completers to the basic ones built into IPCompleter
         sdisp = self.strdispatchers.get('complete_command', StrDispatch())
         self.strdispatchers['complete_command'] = sdisp
         self.Completer.custom_completers = sdisp
 
         self.set_hook('complete_command', module_completer, str_key = 'import')
         self.set_hook('complete_command', module_completer, str_key = 'from')
         self.set_hook('complete_command', module_completer, str_key = '%aimport')
         self.set_hook('complete_command', magic_run_completer, str_key = '%run')
         self.set_hook('complete_command', cd_completer, str_key = '%cd')
         self.set_hook('complete_command', reset_completer, str_key = '%reset')
 
     @skip_doctest
     def complete(self, text, line=None, cursor_pos=None):
         """Return the completed text and a list of completions.
 
         Parameters
         ----------
 
            text : string
              A string of text to be completed on.  It can be given as empty and
              instead a line/position pair are given.  In this case, the
              completer itself will split the line like readline does.
 
            line : string, optional
              The complete line that text is part of.
 
            cursor_pos : int, optional
              The position of the cursor on the input line.
 
         Returns
         -------
         text : string
           The actual text that was completed.
 
         matches : list
           A sorted list with all possible completions.
 
 
         Notes
         -----
         The optional arguments allow the completion to take more context into
         account, and are part of the low-level completion API.
 
         This is a wrapper around the completion mechanism, similar to what
         readline does at the command line when the TAB key is hit.  By
         exposing it as a method, it can be used by other non-readline
         environments (such as GUIs) for text completion.
 
         Examples
         --------
 
         In [1]: x = 'hello'
 
         In [2]: _ip.complete('x.l')
         Out[2]: ('x.l', ['x.ljust', 'x.lower', 'x.lstrip'])
         """
 
         # Inject names into __builtin__ so we can complete on the added names.
         with self.builtin_trap:
             return self.Completer.complete(text, line, cursor_pos)
 
     def set_custom_completer(self, completer, pos=0) -> None:
         """Adds a new custom completer function.
 
         The position argument (defaults to 0) is the index in the completers
         list where you want the completer to be inserted.
 
         `completer` should have the following signature::
 
             def completion(self: Completer, text: string) -> List[str]:
                 raise NotImplementedError
 
         It will be bound to the current Completer instance and pass some text
         and return a list with current completions to suggest to the user.
         """
 
         newcomp = types.MethodType(completer, self.Completer)
         self.Completer.custom_matchers.insert(pos,newcomp)
 
     def set_completer_frame(self, frame=None):
         """Set the frame of the completer."""
         if frame:
             self.Completer.namespace = frame.f_locals
             self.Completer.global_namespace = frame.f_globals
         else:
             self.Completer.namespace = self.user_ns
             self.Completer.global_namespace = self.user_global_ns
 
     #-------------------------------------------------------------------------
     # Things related to magics
     #-------------------------------------------------------------------------
 
     def init_magics(self):
         from IPython.core import magics as m
         self.magics_manager = magic.MagicsManager(shell=self,
                                    parent=self,
                                    user_magics=m.UserMagics(self))
         self.configurables.append(self.magics_manager)
 
         # Expose as public API from the magics manager
         self.register_magics = self.magics_manager.register
 
         self.register_magics(m.AutoMagics, m.BasicMagics, m.CodeMagics,
             m.ConfigMagics, m.DisplayMagics, m.ExecutionMagics,
             m.ExtensionMagics, m.HistoryMagics, m.LoggingMagics,
             m.NamespaceMagics, m.OSMagics, m.PackagingMagics,
             m.PylabMagics, m.ScriptMagics,
         )
         self.register_magics(m.AsyncMagics)
 
         # Register Magic Aliases
         mman = self.magics_manager
         # FIXME: magic aliases should be defined by the Magics classes
         # or in MagicsManager, not here
         mman.register_alias('ed', 'edit')
         mman.register_alias('hist', 'history')
         mman.register_alias('rep', 'recall')
         mman.register_alias('SVG', 'svg', 'cell')
         mman.register_alias('HTML', 'html', 'cell')
         mman.register_alias('file', 'writefile', 'cell')
 
         # FIXME: Move the color initialization to the DisplayHook, which
         # should be split into a prompt manager and displayhook. We probably
         # even need a centralize colors management object.
         self.run_line_magic('colors', self.colors)
 
     # Defined here so that it's included in the documentation
     @functools.wraps(magic.MagicsManager.register_function)
     def register_magic_function(self, func, magic_kind='line', magic_name=None):
         self.magics_manager.register_function(
             func, magic_kind=magic_kind, magic_name=magic_name
         )
 
     def run_line_magic(self, magic_name, line, _stack_depth=1):
         """Execute the given line magic.
 
         Parameters
         ----------
         magic_name : str
             Name of the desired magic function, without '%' prefix.
         line : str
             The rest of the input line as a single string.
         _stack_depth : int
             If run_line_magic() is called from magic() then _stack_depth=2.
             This is added to ensure backward compatibility for use of 'get_ipython().magic()'
         """
         fn = self.find_line_magic(magic_name)
         if fn is None:
             cm = self.find_cell_magic(magic_name)
             etpl = "Line magic function `%%%s` not found%s."
             extra = '' if cm is None else (' (But cell magic `%%%%%s` exists, '
                                     'did you mean that instead?)' % magic_name )
             raise UsageError(etpl % (magic_name, extra))
         else:
             # Note: this is the distance in the stack to the user's frame.
             # This will need to be updated if the internal calling logic gets
             # refactored, or else we'll be expanding the wrong variables.
 
             # Determine stack_depth depending on where run_line_magic() has been called
             stack_depth = _stack_depth
             if getattr(fn, magic.MAGIC_NO_VAR_EXPAND_ATTR, False):
                 # magic has opted out of var_expand
                 magic_arg_s = line
             else:
                 magic_arg_s = self.var_expand(line, stack_depth)
             # Put magic args in a list so we can call with f(*a) syntax
             args = [magic_arg_s]
             kwargs = {}
             # Grab local namespace if we need it:
             if getattr(fn, "needs_local_scope", False):
                 kwargs['local_ns'] = self.get_local_scope(stack_depth)
             with self.builtin_trap:
                 result = fn(*args, **kwargs)
             return result
 
     def get_local_scope(self, stack_depth):
         """Get local scope at given stack depth.
 
         Parameters
         ----------
         stack_depth : int
             Depth relative to calling frame
         """
         return sys._getframe(stack_depth + 1).f_locals
 
     def run_cell_magic(self, magic_name, line, cell):
         """Execute the given cell magic.
 
         Parameters
         ----------
         magic_name : str
             Name of the desired magic function, without '%' prefix.
         line : str
             The rest of the first input line as a single string.
         cell : str
             The body of the cell as a (possibly multiline) string.
         """
         fn = self.find_cell_magic(magic_name)
         if fn is None:
             lm = self.find_line_magic(magic_name)
             etpl = "Cell magic `%%{0}` not found{1}."
             extra = '' if lm is None else (' (But line magic `%{0}` exists, '
                             'did you mean that instead?)'.format(magic_name))
             raise UsageError(etpl.format(magic_name, extra))
         elif cell == '':
             message = '%%{0} is a cell magic, but the cell body is empty.'.format(magic_name)
             if self.find_line_magic(magic_name) is not None:
                 message += ' Did you mean the line magic %{0} (single %)?'.format(magic_name)
             raise UsageError(message)
         else:
             # Note: this is the distance in the stack to the user's frame.
             # This will need to be updated if the internal calling logic gets
             # refactored, or else we'll be expanding the wrong variables.
             stack_depth = 2
             if getattr(fn, magic.MAGIC_NO_VAR_EXPAND_ATTR, False):
                 # magic has opted out of var_expand
                 magic_arg_s = line
             else:
                 magic_arg_s = self.var_expand(line, stack_depth)
             kwargs = {}
             if getattr(fn, "needs_local_scope", False):
                 kwargs['local_ns'] = self.user_ns
 
             with self.builtin_trap:
                 args = (magic_arg_s, cell)
                 result = fn(*args, **kwargs)
             return result
 
     def find_line_magic(self, magic_name):
         """Find and return a line magic by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics['line'].get(magic_name)
 
     def find_cell_magic(self, magic_name):
         """Find and return a cell magic by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics['cell'].get(magic_name)
 
     def find_magic(self, magic_name, magic_kind='line'):
         """Find and return a magic of the given type by name.
 
         Returns None if the magic isn't found."""
         return self.magics_manager.magics[magic_kind].get(magic_name)
 
     def magic(self, arg_s):
         """DEPRECATED. Use run_line_magic() instead.
 
         Call a magic function by name.
 
         Input: a string containing the name of the magic function to call and
         any additional arguments to be passed to the magic.
 
         magic('name -opt foo bar') is equivalent to typing at the ipython
         prompt:
 
         In[1]: %name -opt foo bar
 
         To call a magic without arguments, simply use magic('name').
 
         This provides a proper Python function to call IPython's magics in any
         valid Python code you can type at the interpreter, including loops and
         compound statements.
         """
         # TODO: should we issue a loud deprecation warning here?
         magic_name, _, magic_arg_s = arg_s.partition(' ')
         magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
         return self.run_line_magic(magic_name, magic_arg_s, _stack_depth=2)
 
     #-------------------------------------------------------------------------
     # Things related to macros
     #-------------------------------------------------------------------------
 
     def define_macro(self, name, themacro):
         """Define a new macro
 
         Parameters
         ----------
         name : str
             The name of the macro.
         themacro : str or Macro
             The action to do upon invoking the macro.  If a string, a new
             Macro object is created by passing the string to it.
         """
 
         from IPython.core import macro
 
         if isinstance(themacro, str):
             themacro = macro.Macro(themacro)
         if not isinstance(themacro, macro.Macro):
             raise ValueError('A macro must be a string or a Macro instance.')
         self.user_ns[name] = themacro
 
     #-------------------------------------------------------------------------
     # Things related to the running of system commands
     #-------------------------------------------------------------------------
 
     def system_piped(self, cmd):
         """Call the given cmd in a subprocess, piping stdout/err
 
         Parameters
         ----------
         cmd : str
           Command to execute (can not end in '&', as background processes are
           not supported.  Should not be a command that expects input
           other than simple text.
         """
         if cmd.rstrip().endswith('&'):
             # this is *far* from a rigorous test
             # We do not support backgrounding processes because we either use
             # pexpect or pipes to read from.  Users can always just call
             # os.system() or use ip.system=ip.system_raw
             # if they really want a background process.
             raise OSError("Background processes not supported.")
 
         # we explicitly do NOT return the subprocess status code, because
         # a non-None value would trigger :func:`sys.displayhook` calls.
         # Instead, we store the exit_code in user_ns.
         self.user_ns['_exit_code'] = system(self.var_expand(cmd, depth=1))
 
     def system_raw(self, cmd):
         """Call the given cmd in a subprocess using os.system on Windows or
         subprocess.call using the system shell on other platforms.
 
         Parameters
         ----------
         cmd : str
           Command to execute.
         """
         cmd = self.var_expand(cmd, depth=1)
         # warn if there is an IPython magic alternative.
         main_cmd = cmd.split()[0]
         has_magic_alternatives = ("pip", "conda", "cd", "ls")
 
         # had to check if the command was an alias expanded because of `ls`
         is_alias_expanded = self.alias_manager.is_alias(main_cmd) and (
             self.alias_manager.retrieve_alias(main_cmd).strip() == cmd.strip()
         )
 
         if main_cmd in has_magic_alternatives and not is_alias_expanded:
             warnings.warn(
                 (
                     "You executed the system command !{0} which may not work "
                     "as expected. Try the IPython magic %{0} instead."
                 ).format(main_cmd)
             )
 
         # protect os.system from UNC paths on Windows, which it can't handle:
         if sys.platform == 'win32':
             from IPython.utils._process_win32 import AvoidUNCPath
             with AvoidUNCPath() as path:
                 if path is not None:
                     cmd = '"pushd %s &&"%s' % (path, cmd)
                 try:
                     ec = os.system(cmd)
                 except KeyboardInterrupt:
                     print('\n' + self.get_exception_only(), file=sys.stderr)
                     ec = -2
         else:
             # For posix the result of the subprocess.call() below is an exit
             # code, which by convention is zero for success, positive for
             # program failure.  Exit codes above 128 are reserved for signals,
             # and the formula for converting a signal to an exit code is usually
             # signal_number+128.  To more easily differentiate between exit
             # codes and signals, ipython uses negative numbers.  For instance
             # since control-c is signal 2 but exit code 130, ipython's
             # _exit_code variable will read -2.  Note that some shells like
             # csh and fish don't follow sh/bash conventions for exit codes.
             executable = os.environ.get('SHELL', None)
             try:
                 # Use env shell instead of default /bin/sh
                 ec = subprocess.call(cmd, shell=True, executable=executable)
             except KeyboardInterrupt:
                 # intercept control-C; a long traceback is not useful here
                 print('\n' + self.get_exception_only(), file=sys.stderr)
                 ec = 130
             if ec > 128:
                 ec = -(ec - 128)
 
         # We explicitly do NOT return the subprocess status code, because
         # a non-None value would trigger :func:`sys.displayhook` calls.
         # Instead, we store the exit_code in user_ns.  Note the semantics
         # of _exit_code: for control-c, _exit_code == -signal.SIGNIT,
         # but raising SystemExit(_exit_code) will give status 254!
         self.user_ns['_exit_code'] = ec
 
     # use piped system by default, because it is better behaved
     system = system_piped
 
     def getoutput(self, cmd, split=True, depth=0):
         """Get output (possibly including stderr) from a subprocess.
 
         Parameters
         ----------
         cmd : str
           Command to execute (can not end in '&', as background processes are
           not supported.
         split : bool, optional
           If True, split the output into an IPython SList.  Otherwise, an
           IPython LSString is returned.  These are objects similar to normal
           lists and strings, with a few convenience attributes for easier
           manipulation of line-based output.  You can use '?' on them for
           details.
         depth : int, optional
           How many frames above the caller are the local variables which should
           be expanded in the command string? The default (0) assumes that the
           expansion variables are in the stack frame calling this function.
         """
         if cmd.rstrip().endswith('&'):
             # this is *far* from a rigorous test
             raise OSError("Background processes not supported.")
         out = getoutput(self.var_expand(cmd, depth=depth+1))
         if split:
             out = SList(out.splitlines())
         else:
             out = LSString(out)
         return out
 
     #-------------------------------------------------------------------------
     # Things related to aliases
     #-------------------------------------------------------------------------
 
     def init_alias(self):
         self.alias_manager = AliasManager(shell=self, parent=self)
         self.configurables.append(self.alias_manager)
 
     #-------------------------------------------------------------------------
     # Things related to extensions
     #-------------------------------------------------------------------------
 
     def init_extension_manager(self):
         self.extension_manager = ExtensionManager(shell=self, parent=self)
         self.configurables.append(self.extension_manager)
 
     #-------------------------------------------------------------------------
     # Things related to payloads
     #-------------------------------------------------------------------------
 
     def init_payload(self):
         self.payload_manager = PayloadManager(parent=self)
         self.configurables.append(self.payload_manager)
 
     #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 
     def init_prefilter(self):
         self.prefilter_manager = PrefilterManager(shell=self, parent=self)
         self.configurables.append(self.prefilter_manager)
         # Ultimately this will be refactored in the new interpreter code, but
         # for now, we should expose the main prefilter method (there's legacy
         # code out there that may rely on this).
         self.prefilter = self.prefilter_manager.prefilter_lines
 
     def auto_rewrite_input(self, cmd):
         """Print to the screen the rewritten form of the user's command.
 
         This shows visual feedback by rewriting input lines that cause
         automatic calling to kick in, like::
 
           /f x
 
         into::
 
           ------> f(x)
 
         after the user's input prompt.  This helps the user understand that the
         input line was transformed automatically by IPython.
         """
         if not self.show_rewritten_input:
             return
 
         # This is overridden in TerminalInteractiveShell to use fancy prompts
         print("------> " + cmd)
 
     #-------------------------------------------------------------------------
     # Things related to extracting values/expressions from kernel and user_ns
     #-------------------------------------------------------------------------
 
     def _user_obj_error(self):
         """return simple exception dict
 
         for use in user_expressions
         """
 
         etype, evalue, tb = self._get_exc_info()
         stb = self.InteractiveTB.get_exception_only(etype, evalue)
 
         exc_info = {
             "status": "error",
             "traceback": stb,
             "ename": etype.__name__,
             "evalue": py3compat.safe_unicode(evalue),
         }
 
         return exc_info
 
     def _format_user_obj(self, obj):
         """format a user object to display dict
 
         for use in user_expressions
         """
 
         data, md = self.display_formatter.format(obj)
         value = {
             'status' : 'ok',
             'data' : data,
             'metadata' : md,
         }
         return value
 
     def user_expressions(self, expressions):
         """Evaluate a dict of expressions in the user's namespace.
 
         Parameters
         ----------
         expressions : dict
           A dict with string keys and string values.  The expression values
           should be valid Python expressions, each of which will be evaluated
           in the user namespace.
 
         Returns
         -------
         A dict, keyed like the input expressions dict, with the rich mime-typed
         display_data of each value.
         """
         out = {}
         user_ns = self.user_ns
         global_ns = self.user_global_ns
 
         for key, expr in expressions.items():
             try:
                 value = self._format_user_obj(eval(expr, global_ns, user_ns))
             except:
                 value = self._user_obj_error()
             out[key] = value
         return out
 
     #-------------------------------------------------------------------------
     # Things related to the running of code
     #-------------------------------------------------------------------------
 
     def ex(self, cmd):
         """Execute a normal python statement in user namespace."""
         with self.builtin_trap:
             exec(cmd, self.user_global_ns, self.user_ns)
 
     def ev(self, expr):
         """Evaluate python expression expr in user namespace.
 
         Returns the result of evaluation
         """
         with self.builtin_trap:
             return eval(expr, self.user_global_ns, self.user_ns)
 
     def safe_execfile(self, fname, *where, exit_ignore=False, raise_exceptions=False, shell_futures=False):
         """A safe version of the builtin execfile().
 
         This version will never throw an exception, but instead print
         helpful error messages to the screen.  This only works on pure
         Python files with the .py extension.
 
         Parameters
         ----------
         fname : string
             The name of the file to be executed.
         where : tuple
             One or two namespaces, passed to execfile() as (globals,locals).
             If only one is given, it is passed as both.
         exit_ignore : bool (False)
             If True, then silence SystemExit for non-zero status (it is always
             silenced for zero status, as it is so common).
         raise_exceptions : bool (False)
             If True raise exceptions everywhere. Meant for testing.
         shell_futures : bool (False)
             If True, the code will share future statements with the interactive
             shell. It will both be affected by previous __future__ imports, and
             any __future__ imports in the code will affect the shell. If False,
             __future__ imports are not shared in either direction.
 
         """
         fname = Path(fname).expanduser().resolve()
 
         # Make sure we can open the file
         try:
             with fname.open():
                 pass
         except:
             warn('Could not open file <%s> for safe execution.' % fname)
             return
 
         # Find things also in current directory.  This is needed to mimic the
         # behavior of running a script from the system command line, where
         # Python inserts the script's directory into sys.path
         dname = str(fname.parent)
 
         with prepended_to_syspath(dname), self.builtin_trap:
             try:
                 glob, loc = (where + (None, ))[:2]
                 py3compat.execfile(
                     fname, glob, loc,
                     self.compile if shell_futures else None)
             except SystemExit as status:
                 # If the call was made with 0 or None exit status (sys.exit(0)
                 # or sys.exit() ), don't bother showing a traceback, as both of
                 # these are considered normal by the OS:
                 # > python -c'import sys;sys.exit(0)'; echo $?
                 # 0
                 # > python -c'import sys;sys.exit()'; echo $?
                 # 0
                 # For other exit status, we show the exception unless
                 # explicitly silenced, but only in short form.
                 if status.code:
                     if raise_exceptions:
                         raise
                     if not exit_ignore:
                         self.showtraceback(exception_only=True)
             except:
                 if raise_exceptions:
                     raise
                 # tb offset is 2 because we wrap execfile
                 self.showtraceback(tb_offset=2)
 
     def safe_execfile_ipy(self, fname, shell_futures=False, raise_exceptions=False):
         """Like safe_execfile, but for .ipy or .ipynb files with IPython syntax.
 
         Parameters
         ----------
         fname : str
             The name of the file to execute.  The filename must have a
             .ipy or .ipynb extension.
         shell_futures : bool (False)
             If True, the code will share future statements with the interactive
             shell. It will both be affected by previous __future__ imports, and
             any __future__ imports in the code will affect the shell. If False,
             __future__ imports are not shared in either direction.
         raise_exceptions : bool (False)
             If True raise exceptions everywhere.  Meant for testing.
         """
         fname = Path(fname).expanduser().resolve()
 
         # Make sure we can open the file
         try:
             with fname.open():
                 pass
         except:
             warn('Could not open file <%s> for safe execution.' % fname)
             return
 
         # Find things also in current directory.  This is needed to mimic the
         # behavior of running a script from the system command line, where
         # Python inserts the script's directory into sys.path
         dname = str(fname.parent)
 
         def get_cells():
             """generator for sequence of code blocks to run"""
             if fname.suffix == ".ipynb":
                 from nbformat import read
                 nb = read(fname, as_version=4)
                 if not nb.cells:
                     return
                 for cell in nb.cells:
                     if cell.cell_type == 'code':
                         yield cell.source
             else:
                 yield fname.read_text()
 
         with prepended_to_syspath(dname):
             try:
                 for cell in get_cells():
                     result = self.run_cell(cell, silent=True, shell_futures=shell_futures)
                     if raise_exceptions:
                         result.raise_error()
                     elif not result.success:
                         break
             except:
                 if raise_exceptions:
                     raise
                 self.showtraceback()
                 warn('Unknown failure executing file: <%s>' % fname)
 
     def safe_run_module(self, mod_name, where):
         """A safe version of runpy.run_module().
 
         This version will never throw an exception, but instead print
         helpful error messages to the screen.
 
         `SystemExit` exceptions with status code 0 or None are ignored.
 
         Parameters
         ----------
         mod_name : string
             The name of the module to be executed.
         where : dict
             The globals namespace.
         """
         try:
             try:
                 where.update(
                     runpy.run_module(str(mod_name), run_name="__main__",
                                      alter_sys=True)
                             )
             except SystemExit as status:
                 if status.code:
                     raise
         except:
             self.showtraceback()
             warn('Unknown failure executing module: <%s>' % mod_name)
 
     def run_cell(self, raw_cell, store_history=False, silent=False, shell_futures=True):
         """Run a complete IPython cell.
 
         Parameters
         ----------
         raw_cell : str
           The code (including IPython code such as %magic functions) to run.
         store_history : bool
           If True, the raw and translated cell will be stored in IPython's
           history. For user code calling back into IPython's machinery, this
           should be set to False.
         silent : bool
           If True, avoid side-effects, such as implicit displayhooks and
           and logging.  silent=True forces store_history=False.
         shell_futures : bool
           If True, the code will share future statements with the interactive
           shell. It will both be affected by previous __future__ imports, and
           any __future__ imports in the code will affect the shell. If False,
           __future__ imports are not shared in either direction.
 
         Returns
         -------
         result : :class:`ExecutionResult`
         """
         result = None
         try:
             result = self._run_cell(
                 raw_cell, store_history, silent, shell_futures)
         finally:
             self.events.trigger('post_execute')
             if not silent:
                 self.events.trigger('post_run_cell', result)
         return result
 
     def _run_cell(self, raw_cell:str, store_history:bool, silent:bool, shell_futures:bool) -> ExecutionResult:
         """Internal method to run a complete IPython cell."""
 
         # we need to avoid calling self.transform_cell multiple time on the same thing
         # so we need to store some results:
         preprocessing_exc_tuple = None
         try:
             transformed_cell = self.transform_cell(raw_cell)
         except Exception:
             transformed_cell = raw_cell
             preprocessing_exc_tuple = sys.exc_info()
 
         assert transformed_cell is not None
         coro = self.run_cell_async(
             raw_cell,
             store_history=store_history,
             silent=silent,
             shell_futures=shell_futures,
             transformed_cell=transformed_cell,
             preprocessing_exc_tuple=preprocessing_exc_tuple,
         )
 
         # run_cell_async is async, but may not actually need an eventloop.
         # when this is the case, we want to run it using the pseudo_sync_runner
         # so that code can invoke eventloops (for example via the %run , and
         # `%paste` magic.
         if self.trio_runner:
             runner = self.trio_runner
         elif self.should_run_async(
             raw_cell,
             transformed_cell=transformed_cell,
             preprocessing_exc_tuple=preprocessing_exc_tuple,
         ):
             runner = self.loop_runner
         else:
             runner = _pseudo_sync_runner
 
         try:
             return runner(coro)
         except BaseException as e:
             info = ExecutionInfo(raw_cell, store_history, silent, shell_futures)
             result = ExecutionResult(info)
             result.error_in_exec = e
             self.showtraceback(running_compiled_code=True)
             return result
 
     def should_run_async(
         self, raw_cell: str, *, transformed_cell=None, preprocessing_exc_tuple=None
     ) -> bool:
         """Return whether a cell should be run asynchronously via a coroutine runner
 
         Parameters
         ----------
         raw_cell: str
             The code to be executed
 
         Returns
         -------
         result: bool
             Whether the code needs to be run with a coroutine runner or not
 
         .. versionadded: 7.0
         """
         if not self.autoawait:
             return False
         if preprocessing_exc_tuple is not None:
             return False
         assert preprocessing_exc_tuple is None
         if transformed_cell is None:
             warnings.warn(
                 "`should_run_async` will not call `transform_cell`"
                 " automatically in the future. Please pass the result to"
                 " `transformed_cell` argument and any exception that happen"
                 " during the"
                 "transform in `preprocessing_exc_tuple` in"
                 " IPython 7.17 and above.",
                 DeprecationWarning,
                 stacklevel=2,
             )
             try:
                 cell = self.transform_cell(raw_cell)
             except Exception:
                 # any exception during transform will be raised
                 # prior to execution
                 return False
         else:
             cell = transformed_cell
         return _should_be_async(cell)
 
     async def run_cell_async(
         self,
         raw_cell: str,
         store_history=False,
         silent=False,
         shell_futures=True,
         *,
         transformed_cell: Optional[str] = None,
         preprocessing_exc_tuple: Optional[Any] = None
     ) -> ExecutionResult:
         """Run a complete IPython cell asynchronously.
 
         Parameters
         ----------
         raw_cell : str
           The code (including IPython code such as %magic functions) to run.
         store_history : bool
           If True, the raw and translated cell will be stored in IPython's
           history. For user code calling back into IPython's machinery, this
           should be set to False.
         silent : bool
           If True, avoid side-effects, such as implicit displayhooks and
           and logging.  silent=True forces store_history=False.
         shell_futures : bool
           If True, the code will share future statements with the interactive
           shell. It will both be affected by previous __future__ imports, and
           any __future__ imports in the code will affect the shell. If False,
           __future__ imports are not shared in either direction.
         transformed_cell: str
           cell that was passed through transformers
         preprocessing_exc_tuple:
           trace if the transformation failed.
 
         Returns
         -------
         result : :class:`ExecutionResult`
 
         .. versionadded: 7.0
         """
         info = ExecutionInfo(
             raw_cell, store_history, silent, shell_futures)
         result = ExecutionResult(info)
 
         if (not raw_cell) or raw_cell.isspace():
             self.last_execution_succeeded = True
             self.last_execution_result = result
             return result
 
         if silent:
             store_history = False
 
         if store_history:
             result.execution_count = self.execution_count
 
         def error_before_exec(value):
             if store_history:
                 self.execution_count += 1
             result.error_before_exec = value
             self.last_execution_succeeded = False
             self.last_execution_result = result
             return result
 
         self.events.trigger('pre_execute')
         if not silent:
             self.events.trigger('pre_run_cell', info)
 
         if transformed_cell is None:
             warnings.warn(
                 "`run_cell_async` will not call `transform_cell`"
                 " automatically in the future. Please pass the result to"
                 " `transformed_cell` argument and any exception that happen"
                 " during the"
                 "transform in `preprocessing_exc_tuple` in"
                 " IPython 7.17 and above.",
                 DeprecationWarning,
                 stacklevel=2,
             )
             # If any of our input transformation (input_transformer_manager or
             # prefilter_manager) raises an exception, we store it in this variable
             # so that we can display the error after logging the input and storing
             # it in the history.
             try:
                 cell = self.transform_cell(raw_cell)
             except Exception:
                 preprocessing_exc_tuple = sys.exc_info()
                 cell = raw_cell  # cell has to exist so it can be stored/logged
             else:
                 preprocessing_exc_tuple = None
         else:
             if preprocessing_exc_tuple is None:
                 cell = transformed_cell
             else:
                 cell = raw_cell
 
         # Store raw and processed history
         if store_history:
             self.history_manager.store_inputs(self.execution_count,
                                               cell, raw_cell)
         if not silent:
             self.logger.log(cell, raw_cell)
 
         # Display the exception if input processing failed.
         if preprocessing_exc_tuple is not None:
             self.showtraceback(preprocessing_exc_tuple)
             if store_history:
                 self.execution_count += 1
             return error_before_exec(preprocessing_exc_tuple[1])
 
         # Our own compiler remembers the __future__ environment. If we want to
         # run code with a separate __future__ environment, use the default
         # compiler
         compiler = self.compile if shell_futures else self.compiler_class()
 
         _run_async = False
 
         with self.builtin_trap:
             cell_name = compiler.cache(cell, self.execution_count, raw_code=raw_cell)
 
             with self.display_trap:
                 # Compile to bytecode
                 try:
                     if sys.version_info < (3,8) and self.autoawait:
                         if _should_be_async(cell):
                             # the code AST below will not be user code: we wrap it
                             # in an `async def`. This will likely make some AST
                             # transformer below miss some transform opportunity and
                             # introduce a small coupling to run_code (in which we
                             # bake some assumptions of what _ast_asyncify returns.
                             # they are ways around (like grafting part of the ast
                             # later:
                             #    - Here, return code_ast.body[0].body[1:-1], as well
                             #    as last expression in  return statement which is
                             #    the user code part.
                             #    - Let it go through the AST transformers, and graft
                             #    - it back after the AST transform
                             # But that seem unreasonable, at least while we
                             # do not need it.
                             code_ast = _ast_asyncify(cell, 'async-def-wrapper')
                             _run_async = True
                         else:
                             code_ast = compiler.ast_parse(cell, filename=cell_name)
                     else:
                         code_ast = compiler.ast_parse(cell, filename=cell_name)
                 except self.custom_exceptions as e:
                     etype, value, tb = sys.exc_info()
                     self.CustomTB(etype, value, tb)
                     return error_before_exec(e)
                 except IndentationError as e:
                     self.showindentationerror()
                     return error_before_exec(e)
                 except (OverflowError, SyntaxError, ValueError, TypeError,
                         MemoryError) as e:
                     self.showsyntaxerror()
                     return error_before_exec(e)
 
                 # Apply AST transformations
                 try:
                     code_ast = self.transform_ast(code_ast)
                 except InputRejected as e:
                     self.showtraceback()
                     return error_before_exec(e)
 
                 # Give the displayhook a reference to our ExecutionResult so it
                 # can fill in the output value.
                 self.displayhook.exec_result = result
 
                 # Execute the user code
                 interactivity = "none" if silent else self.ast_node_interactivity
                 if _run_async:
                     interactivity = 'async'
 
                 has_raised = await self.run_ast_nodes(code_ast.body, cell_name,
                        interactivity=interactivity, compiler=compiler, result=result)
 
                 self.last_execution_succeeded = not has_raised
                 self.last_execution_result = result
 
                 # Reset this so later displayed values do not modify the
                 # ExecutionResult
                 self.displayhook.exec_result = None
 
         if store_history:
             # Write output to the database. Does nothing unless
             # history output logging is enabled.
             self.history_manager.store_output(self.execution_count)
             # Each cell is a *single* input, regardless of how many lines it has
             self.execution_count += 1
 
         return result
 
     def transform_cell(self, raw_cell):
         """Transform an input cell before parsing it.
 
         Static transformations, implemented in IPython.core.inputtransformer2,
         deal with things like ``%magic`` and ``!system`` commands.
         These run on all input.
         Dynamic transformations, for things like unescaped magics and the exit
         autocall, depend on the state of the interpreter.
         These only apply to single line inputs.
 
         These string-based transformations are followed by AST transformations;
         see :meth:`transform_ast`.
         """
         # Static input transformations
         cell = self.input_transformer_manager.transform_cell(raw_cell)
 
         if len(cell.splitlines()) == 1:
             # Dynamic transformations - only applied for single line commands
             with self.builtin_trap:
                 # use prefilter_lines to handle trailing newlines
                 # restore trailing newline for ast.parse
                 cell = self.prefilter_manager.prefilter_lines(cell) + '\n'
 
         lines = cell.splitlines(keepends=True)
         for transform in self.input_transformers_post:
             lines = transform(lines)
         cell = ''.join(lines)
 
         return cell
 
     def transform_ast(self, node):
         """Apply the AST transformations from self.ast_transformers
 
         Parameters
         ----------
         node : ast.Node
           The root node to be transformed. Typically called with the ast.Module
           produced by parsing user input.
 
         Returns
         -------
         An ast.Node corresponding to the node it was called with. Note that it
         may also modify the passed object, so don't rely on references to the
         original AST.
         """
         for transformer in self.ast_transformers:
             try:
                 node = transformer.visit(node)
             except InputRejected:
                 # User-supplied AST transformers can reject an input by raising
                 # an InputRejected.  Short-circuit in this case so that we
                 # don't unregister the transform.
                 raise
             except Exception:
                 warn("AST transformer %r threw an error. It will be unregistered." % transformer)
                 self.ast_transformers.remove(transformer)
 
         if self.ast_transformers:
             ast.fix_missing_locations(node)
         return node
 
     async def run_ast_nodes(self, nodelist:ListType[AST], cell_name:str, interactivity='last_expr',
                         compiler=compile, result=None):
         """Run a sequence of AST nodes. The execution mode depends on the
         interactivity parameter.
 
         Parameters
         ----------
         nodelist : list
           A sequence of AST nodes to run.
         cell_name : str
           Will be passed to the compiler as the filename of the cell. Typically
           the value returned by ip.compile.cache(cell).
         interactivity : str
           'all', 'last', 'last_expr' , 'last_expr_or_assign' or 'none',
           specifying which nodes should be run interactively (displaying output
           from expressions). 'last_expr' will run the last node interactively
           only if it is an expression (i.e. expressions in loops or other blocks
           are not displayed) 'last_expr_or_assign' will run the last expression
           or the last assignment. Other values for this parameter will raise a
           ValueError.
 
           Experimental value: 'async' Will try to run top level interactive
           async/await code in default runner, this will not respect the
           interactivity setting and will only run the last node if it is an
           expression.
 
         compiler : callable
           A function with the same interface as the built-in compile(), to turn
           the AST nodes into code objects. Default is the built-in compile().
         result : ExecutionResult, optional
           An object to store exceptions that occur during execution.
 
         Returns
         -------
         True if an exception occurred while running code, False if it finished
         running.
         """
         if not nodelist:
             return
 
         if interactivity == 'last_expr_or_assign':
             if isinstance(nodelist[-1], _assign_nodes):
                 asg = nodelist[-1]
                 if isinstance(asg, ast.Assign) and len(asg.targets) == 1:
                     target = asg.targets[0]
                 elif isinstance(asg, _single_targets_nodes):
                     target = asg.target
                 else:
                     target = None
                 if isinstance(target, ast.Name):
                     nnode = ast.Expr(ast.Name(target.id, ast.Load()))
                     ast.fix_missing_locations(nnode)
                     nodelist.append(nnode)
             interactivity = 'last_expr'
 
         _async = False
         if interactivity == 'last_expr':
             if isinstance(nodelist[-1], ast.Expr):
                 interactivity = "last"
             else:
                 interactivity = "none"
 
         if interactivity == 'none':
             to_run_exec, to_run_interactive = nodelist, []
         elif interactivity == 'last':
             to_run_exec, to_run_interactive = nodelist[:-1], nodelist[-1:]
         elif interactivity == 'all':
             to_run_exec, to_run_interactive = [], nodelist
         elif interactivity == 'async':
             to_run_exec, to_run_interactive = [], nodelist
             _async = True
         else:
             raise ValueError("Interactivity was %r" % interactivity)
 
         try:
             if _async and sys.version_info > (3,8):
                 raise ValueError("This branch should never happen on Python 3.8 and above, "
                                  "please try to upgrade IPython and open a bug report with your case.")
             if _async:
                 # If interactivity is async the semantics of run_code are
                 # completely different Skip usual machinery.
                 mod = Module(nodelist, [])
                 async_wrapper_code = compiler(mod, cell_name, 'exec')
                 exec(async_wrapper_code, self.user_global_ns, self.user_ns)
                 async_code = removed_co_newlocals(self.user_ns.pop('async-def-wrapper')).__code__
                 if (await self.run_code(async_code, result, async_=True)):
                     return True
             else:
                 if sys.version_info > (3, 8):
                     def compare(code):
                         is_async = (inspect.CO_COROUTINE & code.co_flags == inspect.CO_COROUTINE)
                         return is_async
                 else:
                     def compare(code):
                         return _async
 
                 # refactor that to just change the mod constructor.
                 to_run = []
                 for node in to_run_exec:
                     to_run.append((node, 'exec'))
 
                 for node in to_run_interactive:
                     to_run.append((node, 'single'))
 
                 for node,mode in to_run:
                     if mode == 'exec':
                         mod = Module([node], [])
                     elif mode == 'single':
                         mod = ast.Interactive([node])
                     with compiler.extra_flags(getattr(ast, 'PyCF_ALLOW_TOP_LEVEL_AWAIT', 0x0) if self.autoawait else 0x0):
                         code = compiler(mod, cell_name, mode)
                         asy = compare(code)
                     if (await self.run_code(code, result,  async_=asy)):
                         return True
 
             # Flush softspace
             if softspace(sys.stdout, 0):
                 print()
 
         except:
             # It's possible to have exceptions raised here, typically by
             # compilation of odd code (such as a naked 'return' outside a
             # function) that did parse but isn't valid. Typically the exception
             # is a SyntaxError, but it's safest just to catch anything and show
             # the user a traceback.
 
             # We do only one try/except outside the loop to minimize the impact
             # on runtime, and also because if any node in the node list is
             # broken, we should stop execution completely.
             if result:
                 result.error_before_exec = sys.exc_info()[1]
             self.showtraceback()
             return True
 
         return False
 
     def _async_exec(self, code_obj: types.CodeType, user_ns: dict):
         """
         Evaluate an asynchronous code object using a code runner
 
         Fake asynchronous execution of code_object in a namespace via a proxy namespace.
 
         Returns coroutine object, which can be executed via async loop runner
 
         WARNING: The semantics of `async_exec` are quite different from `exec`,
         in particular you can only pass a single namespace. It also return a
         handle to the value of the last things returned by code_object.
         """
 
         return eval(code_obj, user_ns)
 
     async def run_code(self, code_obj, result=None, *, async_=False):
         """Execute a code object.
 
         When an exception occurs, self.showtraceback() is called to display a
         traceback.
 
         Parameters
         ----------
         code_obj : code object
           A compiled code object, to be executed
         result : ExecutionResult, optional
           An object to store exceptions that occur during execution.
         async_ :  Bool (Experimental)
           Attempt to run top-level asynchronous code in a default loop.
 
         Returns
         -------
         False : successful execution.
         True : an error occurred.
         """
         # special value to say that anything above is IPython and should be
         # hidden.
         __tracebackhide__ = "__ipython_bottom__"
         # Set our own excepthook in case the user code tries to call it
         # directly, so that the IPython crash handler doesn't get triggered
         old_excepthook, sys.excepthook = sys.excepthook, self.excepthook
 
         # we save the original sys.excepthook in the instance, in case config
         # code (such as magics) needs access to it.
         self.sys_excepthook = old_excepthook
         outflag = True  # happens in more places, so it's easier as default
         try:
             try:
                 self.hooks.pre_run_code_hook()
                 if async_ and sys.version_info < (3,8):
                     last_expr = (await self._async_exec(code_obj, self.user_ns))
                     code = compile('last_expr', 'fake', "single")
                     exec(code, {'last_expr': last_expr})
                 elif async_ :
                     await eval(code_obj, self.user_global_ns, self.user_ns)
                 else:
                     exec(code_obj, self.user_global_ns, self.user_ns)
             finally:
                 # Reset our crash handler in place
                 sys.excepthook = old_excepthook
         except SystemExit as e:
             if result is not None:
                 result.error_in_exec = e
             self.showtraceback(exception_only=True)
             warn("To exit: use 'exit', 'quit', or Ctrl-D.", stacklevel=1)
         except self.custom_exceptions:
             etype, value, tb = sys.exc_info()
             if result is not None:
                 result.error_in_exec = value
             self.CustomTB(etype, value, tb)
         except:
             if result is not None:
                 result.error_in_exec = sys.exc_info()[1]
             self.showtraceback(running_compiled_code=True)
         else:
             outflag = False
         return outflag
 
     # For backwards compatibility
     runcode = run_code
 
     def check_complete(self, code: str) -> Tuple[str, str]:
         """Return whether a block of code is ready to execute, or should be continued
 
         Parameters
         ----------
         source : string
           Python input code, which can be multiline.
 
         Returns
         -------
         status : str
           One of 'complete', 'incomplete', or 'invalid' if source is not a
           prefix of valid code.
         indent : str
           When status is 'incomplete', this is some whitespace to insert on
           the next line of the prompt.
         """
         status, nspaces = self.input_transformer_manager.check_complete(code)
         return status, ' ' * (nspaces or 0)
 
     #-------------------------------------------------------------------------
     # Things related to GUI support and pylab
     #-------------------------------------------------------------------------
 
     active_eventloop = None
 
     def enable_gui(self, gui=None):
         raise NotImplementedError('Implement enable_gui in a subclass')
 
     def enable_matplotlib(self, gui=None):
         """Enable interactive matplotlib and inline figure support.
 
         This takes the following steps:
 
         1. select the appropriate eventloop and matplotlib backend
         2. set up matplotlib for interactive use with that backend
         3. configure formatters for inline figure display
         4. enable the selected gui eventloop
 
         Parameters
         ----------
         gui : optional, string
           If given, dictates the choice of matplotlib GUI backend to use
           (should be one of IPython's supported backends, 'qt', 'osx', 'tk',
           'gtk', 'wx' or 'inline'), otherwise we use the default chosen by
           matplotlib (as dictated by the matplotlib build-time options plus the
           user's matplotlibrc configuration file).  Note that not all backends
           make sense in all contexts, for example a terminal ipython can't
           display figures inline.
         """
         from IPython.core import pylabtools as pt
         from matplotlib_inline.backend_inline import configure_inline_support
         gui, backend = pt.find_gui_and_backend(gui, self.pylab_gui_select)
 
         if gui != 'inline':
             # If we have our first gui selection, store it
             if self.pylab_gui_select is None:
                 self.pylab_gui_select = gui
             # Otherwise if they are different
             elif gui != self.pylab_gui_select:
                 print('Warning: Cannot change to a different GUI toolkit: %s.'
                         ' Using %s instead.' % (gui, self.pylab_gui_select))
                 gui, backend = pt.find_gui_and_backend(self.pylab_gui_select)
 
         pt.activate_matplotlib(backend)
         configure_inline_support(self, backend)
 
         # Now we must activate the gui pylab wants to use, and fix %run to take
         # plot updates into account
         self.enable_gui(gui)
         self.magics_manager.registry['ExecutionMagics'].default_runner = \
             pt.mpl_runner(self.safe_execfile)
 
         return gui, backend
 
     def enable_pylab(self, gui=None, import_all=True, welcome_message=False):
         """Activate pylab support at runtime.
 
         This turns on support for matplotlib, preloads into the interactive
         namespace all of numpy and pylab, and configures IPython to correctly
         interact with the GUI event loop.  The GUI backend to be used can be
         optionally selected with the optional ``gui`` argument.
 
         This method only adds preloading the namespace to InteractiveShell.enable_matplotlib.
 
         Parameters
         ----------
         gui : optional, string
           If given, dictates the choice of matplotlib GUI backend to use
           (should be one of IPython's supported backends, 'qt', 'osx', 'tk',
           'gtk', 'wx' or 'inline'), otherwise we use the default chosen by
           matplotlib (as dictated by the matplotlib build-time options plus the
           user's matplotlibrc configuration file).  Note that not all backends
           make sense in all contexts, for example a terminal ipython can't
           display figures inline.
         import_all : optional, bool, default: True
           Whether to do `from numpy import *` and `from pylab import *`
           in addition to module imports.
         welcome_message : deprecated
           This argument is ignored, no welcome message will be displayed.
         """
         from IPython.core.pylabtools import import_pylab
 
         gui, backend = self.enable_matplotlib(gui)
 
         # We want to prevent the loading of pylab to pollute the user's
         # namespace as shown by the %who* magics, so we execute the activation
         # code in an empty namespace, and we update *both* user_ns and
         # user_ns_hidden with this information.
         ns = {}
         import_pylab(ns, import_all)
         # warn about clobbered names
         ignored = {"__builtins__"}
         both = set(ns).intersection(self.user_ns).difference(ignored)
         clobbered = [ name for name in both if self.user_ns[name] is not ns[name] ]
         self.user_ns.update(ns)
         self.user_ns_hidden.update(ns)
         return gui, backend, clobbered
 
     #-------------------------------------------------------------------------
     # Utilities
     #-------------------------------------------------------------------------
 
     def var_expand(self, cmd, depth=0, formatter=DollarFormatter()):
         """Expand python variables in a string.
 
         The depth argument indicates how many frames above the caller should
         be walked to look for the local namespace where to expand variables.
 
         The global namespace for expansion is always the user's interactive
         namespace.
         """
         ns = self.user_ns.copy()
         try:
             frame = sys._getframe(depth+1)
         except ValueError:
             # This is thrown if there aren't that many frames on the stack,
             # e.g. if a script called run_line_magic() directly.
             pass
         else:
             ns.update(frame.f_locals)
 
         try:
             # We have to use .vformat() here, because 'self' is a valid and common
             # name, and expanding **ns for .format() would make it collide with
             # the 'self' argument of the method.
             cmd = formatter.vformat(cmd, args=[], kwargs=ns)
         except Exception:
             # if formatter couldn't format, just let it go untransformed
             pass
         return cmd
 
     def mktempfile(self, data=None, prefix='ipython_edit_'):
         """Make a new tempfile and return its filename.
 
         This makes a call to tempfile.mkstemp (created in a tempfile.mkdtemp),
         but it registers the created filename internally so ipython cleans it up
         at exit time.
 
         Optional inputs:
 
           - data(None): if data is given, it gets written out to the temp file
             immediately, and the file is closed again."""
 
         dir_path = Path(tempfile.mkdtemp(prefix=prefix))
         self.tempdirs.append(dir_path)
 
         handle, filename = tempfile.mkstemp(".py", prefix, dir=str(dir_path))
         os.close(handle)  # On Windows, there can only be one open handle on a file
 
         file_path = Path(filename)
         self.tempfiles.append(file_path)
 
         if data:
             file_path.write_text(data)
         return filename
 
     @undoc
     def write(self,data):
         """DEPRECATED: Write a string to the default output"""
         warn('InteractiveShell.write() is deprecated, use sys.stdout instead',
              DeprecationWarning, stacklevel=2)
         sys.stdout.write(data)
 
     @undoc
     def write_err(self,data):
         """DEPRECATED: Write a string to the default error output"""
         warn('InteractiveShell.write_err() is deprecated, use sys.stderr instead',
              DeprecationWarning, stacklevel=2)
         sys.stderr.write(data)
 
     def ask_yes_no(self, prompt, default=None, interrupt=None):
         if self.quiet:
             return True
         return ask_yes_no(prompt,default,interrupt)
 
     def show_usage(self):
         """Show a usage message"""
         page.page(IPython.core.usage.interactive_usage)
 
     def extract_input_lines(self, range_str, raw=False):
         """Return as a string a set of input history slices.
 
         Parameters
         ----------
-        range_str : string
+        range_str : str
             The set of slices is given as a string, like "~5/6-~4/2 4:8 9",
             since this function is for use by magic functions which get their
             arguments as strings. The number before the / is the session
             number: ~n goes n back from the current session.
 
+            If empty string is given, returns history of current session
+            without the last input.
+
         raw : bool, optional
             By default, the processed input is used.  If this is true, the raw
             input history is used instead.
 
         Notes
         -----
 
         Slices can be described with two notations:
 
         * ``N:M`` -> standard python form, means including items N...(M-1).
         * ``N-M`` -> include items N..M (closed endpoint).
         """
         lines = self.history_manager.get_range_by_str(range_str, raw=raw)
-        return "\n".join(x for _, _, x in lines)
+        text = "\n".join(x for _, _, x in lines)
+
+        # Skip the last line, as it's probably the magic that called this
+        if not range_str:
+            if "\n" not in text:
+                text = ""
+            else:
+                text = text[: text.rfind("\n")]
+
+        return text
 
     def find_user_code(self, target, raw=True, py_only=False, skip_encoding_cookie=True, search_ns=False):
         """Get a code string from history, file, url, or a string or macro.
 
         This is mainly used by magic functions.
 
         Parameters
         ----------
-
         target : str
-
           A string specifying code to retrieve. This will be tried respectively
           as: ranges of input history (see %history for syntax), url,
           corresponding .py file, filename, or an expression evaluating to a
           string or Macro in the user namespace.
 
+          If empty string is given, returns complete history of current
+          session, without the last line.
+
         raw : bool
           If true (default), retrieve raw history. Has no effect on the other
           retrieval mechanisms.
 
         py_only : bool (default False)
           Only try to fetch python code, do not try alternative methods to decode file
           if unicode fails.
 
         Returns
         -------
         A string of code.
 
         ValueError is raised if nothing is found, and TypeError if it evaluates
         to an object of another type. In each case, .args[0] is a printable
         message.
         """
         code = self.extract_input_lines(target, raw=raw)  # Grab history
         if code:
             return code
         try:
             if target.startswith(('http://', 'https://')):
                 return openpy.read_py_url(target, skip_encoding_cookie=skip_encoding_cookie)
         except UnicodeDecodeError as e:
             if not py_only :
                 # Deferred import
                 from urllib.request import urlopen
                 response = urlopen(target)
                 return response.read().decode('latin1')
             raise ValueError(("'%s' seem to be unreadable.") % target) from e
 
         potential_target = [target]
         try :
             potential_target.insert(0,get_py_filename(target))
         except IOError:
             pass
 
         for tgt in potential_target :
             if os.path.isfile(tgt):                        # Read file
                 try :
                     return openpy.read_py_file(tgt, skip_encoding_cookie=skip_encoding_cookie)
                 except UnicodeDecodeError as e:
                     if not py_only :
                         with io_open(tgt,'r', encoding='latin1') as f :
                             return f.read()
                     raise ValueError(("'%s' seem to be unreadable.") % target) from e
             elif os.path.isdir(os.path.expanduser(tgt)):
                 raise ValueError("'%s' is a directory, not a regular file." % target)
 
         if search_ns:
             # Inspect namespace to load object source
             object_info = self.object_inspect(target, detail_level=1)
             if object_info['found'] and object_info['source']:
                 return object_info['source']
 
         try:                                              # User namespace
             codeobj = eval(target, self.user_ns)
         except Exception as e:
             raise ValueError(("'%s' was not found in history, as a file, url, "
                                 "nor in the user namespace.") % target) from e
 
         if isinstance(codeobj, str):
             return codeobj
         elif isinstance(codeobj, Macro):
             return codeobj.value
 
         raise TypeError("%s is neither a string nor a macro." % target,
                         codeobj)
 
     def _atexit_once(self):
         """
         At exist operation that need to be called at most once.
         Second call to this function per instance will do nothing.
         """
 
         if not getattr(self, "_atexit_once_called", False):
             self._atexit_once_called = True
             # Clear all user namespaces to release all references cleanly.
             self.reset(new_session=False)
             # Close the history session (this stores the end time and line count)
             # this must be *before* the tempfile cleanup, in case of temporary
             # history db
             self.history_manager.end_session()
             self.history_manager = None
 
     #-------------------------------------------------------------------------
     # Things related to IPython exiting
     #-------------------------------------------------------------------------
     def atexit_operations(self):
         """This will be executed at the time of exit.
 
         Cleanup operations and saving of persistent data that is done
         unconditionally by IPython should be performed here.
 
         For things that may depend on startup flags or platform specifics (such
         as having readline or not), register a separate atexit function in the
         code that has the appropriate information, rather than trying to
         clutter
         """
         self._atexit_once()
 
         # Cleanup all tempfiles and folders left around
         for tfile in self.tempfiles:
             try:
                 tfile.unlink()
                 self.tempfiles.remove(tfile)
             except FileNotFoundError:
                 pass
         del self.tempfiles
         for tdir in self.tempdirs:
             try:
                 tdir.rmdir()
                 self.tempdirs.remove(tdir)
             except FileNotFoundError:
                 pass
         del self.tempdirs
 
 
         # Run user hooks
         self.hooks.shutdown_hook()
 
     def cleanup(self):
         self.restore_sys_module_state()
 
 
     # Overridden in terminal subclass to change prompts
     def switch_doctest_mode(self, mode):
         pass
 
 
 class InteractiveShellABC(metaclass=abc.ABCMeta):
     """An abstract base class for InteractiveShell."""
 
 InteractiveShellABC.register(InteractiveShell)

IPython/core/magics/code.py

@@ -1,750 +1,754 b''
 """Implementation of code management magic functions.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012 The IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import inspect
 import io
 import os
 import re
 import sys
 import ast
 from itertools import chain
 from urllib.request import Request, urlopen
 from urllib.parse import urlencode
 from pathlib import Path
 
 # Our own packages
 from IPython.core.error import TryNext, StdinNotImplementedError, UsageError
 from IPython.core.macro import Macro
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.oinspect import find_file, find_source_lines
 from IPython.core.release import version
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.contexts import preserve_keys
 from IPython.utils.path import get_py_filename
 from warnings import warn
 from logging import error
 from IPython.utils.text import get_text_list
 
 #-----------------------------------------------------------------------------
 # Magic implementation classes
 #-----------------------------------------------------------------------------
 
 # Used for exception handling in magic_edit
 class MacroToEdit(ValueError): pass
 
 ipython_input_pat = re.compile(r"<ipython\-input\-(\d+)-[a-z\d]+>$")
 
 # To match, e.g. 8-10 1:5 :10 3-
 range_re = re.compile(r"""
 (?P<start>\d+)?
 ((?P<sep>[\-:])
  (?P<end>\d+)?)?
 $""", re.VERBOSE)
 
 
 def extract_code_ranges(ranges_str):
     """Turn a string of range for %%load into 2-tuples of (start, stop)
     ready to use as a slice of the content split by lines.
 
     Examples
     --------
     list(extract_input_ranges("5-10 2"))
     [(4, 10), (1, 2)]
     """
     for range_str in ranges_str.split():
         rmatch = range_re.match(range_str)
         if not rmatch:
             continue
         sep = rmatch.group("sep")
         start = rmatch.group("start")
         end = rmatch.group("end")
 
         if sep == '-':
             start = int(start) - 1 if start else None
             end = int(end) if end else None
         elif sep == ':':
             start = int(start) - 1 if start else None
             end = int(end) - 1 if end else None
         else:
             end = int(start)
             start = int(start) - 1
         yield (start, end)
 
 
 def extract_symbols(code, symbols):
     """
     Return a tuple  (blocks, not_found)
     where ``blocks`` is a list of code fragments
     for each symbol parsed from code, and ``not_found`` are
     symbols not found in the code.
 
     For example::
 
         In [1]: code = '''a = 10
            ...: def b(): return 42
            ...: class A: pass'''
 
         In [2]: extract_symbols(code, 'A,b,z')
         Out[2]: (['class A: pass\\n', 'def b(): return 42\\n'], ['z'])
     """
     symbols = symbols.split(',')
 
     # this will raise SyntaxError if code isn't valid Python
     py_code = ast.parse(code)
 
     marks = [(getattr(s, 'name', None), s.lineno) for s in py_code.body]
     code = code.split('\n')
 
     symbols_lines = {}
     
     # we already know the start_lineno of each symbol (marks). 
     # To find each end_lineno, we traverse in reverse order until each 
     # non-blank line
     end = len(code)  
     for name, start in reversed(marks):
         while not code[end - 1].strip():
             end -= 1
         if name:
             symbols_lines[name] = (start - 1, end)
         end = start - 1
 
     # Now symbols_lines is a map
     # {'symbol_name': (start_lineno, end_lineno), ...}
     
     # fill a list with chunks of codes for each requested symbol
     blocks = []
     not_found = []
     for symbol in symbols:
         if symbol in symbols_lines:
             start, end = symbols_lines[symbol]
             blocks.append('\n'.join(code[start:end]) + '\n')
         else:
             not_found.append(symbol)
 
     return blocks, not_found
 
 def strip_initial_indent(lines):
     """For %load, strip indent from lines until finding an unindented line.
 
     https://github.com/ipython/ipython/issues/9775
     """
     indent_re = re.compile(r'\s+')
 
     it = iter(lines)
     first_line = next(it)
     indent_match = indent_re.match(first_line)
 
     if indent_match:
         # First line was indented
         indent = indent_match.group()
         yield first_line[len(indent):]
 
         for line in it:
             if line.startswith(indent):
                 yield line[len(indent):]
             else:
                 # Less indented than the first line - stop dedenting
                 yield line
                 break
     else:
         yield first_line
 
     # Pass the remaining lines through without dedenting
     for line in it:
         yield line
 
 
 class InteractivelyDefined(Exception):
     """Exception for interactively defined variable in magic_edit"""
     def __init__(self, index):
         self.index = index
 
 
 @magics_class
 class CodeMagics(Magics):
     """Magics related to code management (loading, saving, editing, ...)."""
 
     def __init__(self, *args, **kwargs):
         self._knowntemps = set()
         super(CodeMagics, self).__init__(*args, **kwargs)
 
     @line_magic
     def save(self, parameter_s=''):
         """Save a set of lines or a macro to a given filename.
 
         Usage:\\
           %save [options] filename n1-n2 n3-n4 ... n5 .. n6 ...
 
         Options:
 
           -r: use 'raw' input.  By default, the 'processed' history is used,
           so that magics are loaded in their transformed version to valid
           Python.  If this option is given, the raw input as typed as the
           command line is used instead.
           
           -f: force overwrite.  If file exists, %save will prompt for overwrite
           unless -f is given.
 
           -a: append to the file instead of overwriting it.
 
         This function uses the same syntax as %history for input ranges,
         then saves the lines to the filename you specify.
 
+        If no ranges are specified, saves history of the current session up to
+        this point.
+
         It adds a '.py' extension to the file if you don't do so yourself, and
         it asks for confirmation before overwriting existing files.
 
         If `-r` option is used, the default extension is `.ipy`.
         """
 
         opts,args = self.parse_options(parameter_s,'fra',mode='list')
         if not args:
             raise UsageError('Missing filename.')
         raw = 'r' in opts
         force = 'f' in opts
         append = 'a' in opts
         mode = 'a' if append else 'w'
         ext = '.ipy' if raw else '.py'
         fname, codefrom = args[0], " ".join(args[1:])
         if not fname.endswith(('.py','.ipy')):
             fname += ext
         file_exists = os.path.isfile(fname)
         if file_exists and not force and not append:
             try:
                 overwrite = self.shell.ask_yes_no('File `%s` exists. Overwrite (y/[N])? ' % fname, default='n')
             except StdinNotImplementedError:
                 print("File `%s` exists. Use `%%save -f %s` to force overwrite" % (fname, parameter_s))
                 return
             if not overwrite :
                 print('Operation cancelled.')
                 return
         try:
             cmds = self.shell.find_user_code(codefrom,raw)
         except (TypeError, ValueError) as e:
             print(e.args[0])
             return
         with io.open(fname, mode, encoding="utf-8") as f:
             if not file_exists or not append:
                 f.write("# coding: utf-8\n")
             f.write(cmds)
             # make sure we end on a newline
             if not cmds.endswith('\n'):
                 f.write('\n')
         print('The following commands were written to file `%s`:' % fname)
         print(cmds)
 
     @line_magic
     def pastebin(self, parameter_s=''):
         """Upload code to dpaste.com, returning the URL.
 
         Usage:\\
           %pastebin [-d "Custom description"][-e 24] 1-7
 
         The argument can be an input history range, a filename, or the name of a
         string or macro.
 
+        If no arguments are given, uploads the history of this session up to
+        this point.
+
         Options:
 
           -d: Pass a custom description. The default will say
               "Pasted from IPython".
           -e: Pass number of days for the link to be expired.
               The default will be 7 days.
         """
         opts, args = self.parse_options(parameter_s, "d:e:")
 
         try:
             code = self.shell.find_user_code(args)
         except (ValueError, TypeError) as e:
             print(e.args[0])
             return
 
         expiry_days = 7
         try:
             expiry_days = int(opts.get("e", 7))
         except ValueError as e:
             print(e.args[0].capitalize())
             return
         if expiry_days < 1 or expiry_days > 365:
             print("Expiry days should be in range of 1 to 365")
             return
 
         post_data = urlencode(
             {
                 "title": opts.get("d", "Pasted from IPython"),
                 "syntax": "python",
                 "content": code,
                 "expiry_days": expiry_days,
             }
         ).encode("utf-8")
 
         request = Request(
             "https://dpaste.com/api/v2/",
             headers={"User-Agent": "IPython v{}".format(version)},
         )
         response = urlopen(request, post_data)
         return response.headers.get('Location')
 
     @line_magic
     def loadpy(self, arg_s):
         """Alias of `%load`
 
         `%loadpy` has gained some flexibility and dropped the requirement of a `.py`
         extension. So it has been renamed simply into %load. You can look at
         `%load`'s docstring for more info.
         """
         self.load(arg_s)
 
     @line_magic
     def load(self, arg_s):
         """Load code into the current frontend.
 
         Usage:\\
           %load [options] source
 
           where source can be a filename, URL, input history range, macro, or
           element in the user namespace
 
+        If no arguments are given, loads the history of this session up to this
+        point.
+
         Options:
 
           -r <lines>: Specify lines or ranges of lines to load from the source.
           Ranges could be specified as x-y (x..y) or in python-style x:y 
           (x..(y-1)). Both limits x and y can be left blank (meaning the 
           beginning and end of the file, respectively).
 
           -s <symbols>: Specify function or classes to load from python source. 
 
           -y : Don't ask confirmation for loading source above 200 000 characters.
 
           -n : Include the user's namespace when searching for source code.
 
         This magic command can either take a local filename, a URL, an history
         range (see %history) or a macro as argument, it will prompt for
         confirmation before loading source with more than 200 000 characters, unless
         -y flag is passed or if the frontend does not support raw_input::
 
+        %load
         %load myscript.py
         %load 7-27
         %load myMacro
         %load http://www.example.com/myscript.py
         %load -r 5-10 myscript.py
         %load -r 10-20,30,40: foo.py
         %load -s MyClass,wonder_function myscript.py
         %load -n MyClass
         %load -n my_module.wonder_function
         """
         opts,args = self.parse_options(arg_s,'yns:r:')
-
-        if not args:
-            raise UsageError('Missing filename, URL, input history range, '
-                             'macro, or element in the user namespace.')
-
         search_ns = 'n' in opts
-
         contents = self.shell.find_user_code(args, search_ns=search_ns)
 
         if 's' in opts:
             try:
                 blocks, not_found = extract_symbols(contents, opts['s'])
             except SyntaxError:
                 # non python code
                 error("Unable to parse the input as valid Python code")
                 return
 
             if len(not_found) == 1:
                 warn('The symbol `%s` was not found' % not_found[0])
             elif len(not_found) > 1:
                 warn('The symbols %s were not found' % get_text_list(not_found,
                                                                      wrap_item_with='`')
                 )
 
             contents = '\n'.join(blocks)
 
         if 'r' in opts:
             ranges = opts['r'].replace(',', ' ')
             lines = contents.split('\n')
             slices = extract_code_ranges(ranges)
             contents = [lines[slice(*slc)] for slc in slices]
             contents = '\n'.join(strip_initial_indent(chain.from_iterable(contents)))
 
         l = len(contents)
 
         # 200 000 is ~ 2500 full 80 character lines
         # so in average, more than 5000 lines
         if l > 200000 and 'y' not in opts:
             try:
                 ans = self.shell.ask_yes_no(("The text you're trying to load seems pretty big"\
                 " (%d characters). Continue (y/[N]) ?" % l), default='n' )
             except StdinNotImplementedError:
                 #assume yes if raw input not implemented
                 ans = True
 
             if ans is False :
                 print('Operation cancelled.')
                 return
 
         contents = "# %load {}\n".format(arg_s) + contents
 
         self.shell.set_next_input(contents, replace=True)
 
     @staticmethod
     def _find_edit_target(shell, args, opts, last_call):
         """Utility method used by magic_edit to find what to edit."""
 
         def make_filename(arg):
             "Make a filename from the given args"
             try:
                 filename = get_py_filename(arg)
             except IOError:
                 # If it ends with .py but doesn't already exist, assume we want
                 # a new file.
                 if arg.endswith('.py'):
                     filename = arg
                 else:
                     filename = None
             return filename
 
         # Set a few locals from the options for convenience:
         opts_prev = 'p' in opts
         opts_raw = 'r' in opts
 
         # custom exceptions
         class DataIsObject(Exception): pass
 
         # Default line number value
         lineno = opts.get('n',None)
 
         if opts_prev:
             args = '_%s' % last_call[0]
             if args not in shell.user_ns:
                 args = last_call[1]
 
         # by default this is done with temp files, except when the given
         # arg is a filename
         use_temp = True
 
         data = ''
 
         # First, see if the arguments should be a filename.
         filename = make_filename(args)
         if filename:
             use_temp = False
         elif args:
             # Mode where user specifies ranges of lines, like in %macro.
             data = shell.extract_input_lines(args, opts_raw)
             if not data:
                 try:
                     # Load the parameter given as a variable. If not a string,
                     # process it as an object instead (below)
 
                     #print '*** args',args,'type',type(args)  # dbg
                     data = eval(args, shell.user_ns)
                     if not isinstance(data, str):
                         raise DataIsObject
 
                 except (NameError,SyntaxError):
                     # given argument is not a variable, try as a filename
                     filename = make_filename(args)
                     if filename is None:
                         warn("Argument given (%s) can't be found as a variable "
                              "or as a filename." % args)
                         return (None, None, None)
                     use_temp = False
 
                 except DataIsObject as e:
                     # macros have a special edit function
                     if isinstance(data, Macro):
                         raise MacroToEdit(data) from e
 
                     # For objects, try to edit the file where they are defined
                     filename = find_file(data)
                     if filename:
                         if 'fakemodule' in filename.lower() and \
                             inspect.isclass(data):
                             # class created by %edit? Try to find source
                             # by looking for method definitions instead, the
                             # __module__ in those classes is FakeModule.
                             attrs = [getattr(data, aname) for aname in dir(data)]
                             for attr in attrs:
                                 if not inspect.ismethod(attr):
                                     continue
                                 filename = find_file(attr)
                                 if filename and \
                                   'fakemodule' not in filename.lower():
                                     # change the attribute to be the edit
                                     # target instead
                                     data = attr
                                     break
                         
                         m = ipython_input_pat.match(os.path.basename(filename))
                         if m:
                             raise InteractivelyDefined(int(m.groups()[0])) from e
 
                         datafile = 1
                     if filename is None:
                         filename = make_filename(args)
                         datafile = 1
                         if filename is not None:
                             # only warn about this if we get a real name
                             warn('Could not find file where `%s` is defined.\n'
                              'Opening a file named `%s`' % (args, filename))
                     # Now, make sure we can actually read the source (if it was
                     # in a temp file it's gone by now).
                     if datafile:
                         if lineno is None:
                             lineno = find_source_lines(data)
                         if lineno is None:
                             filename = make_filename(args)
                             if filename is None:
                                 warn('The file where `%s` was defined '
                                      'cannot be read or found.' % data)
                                 return (None, None, None)
                     use_temp = False
 
         if use_temp:
             filename = shell.mktempfile(data)
             print('IPython will make a temporary file named:',filename)
 
         # use last_call to remember the state of the previous call, but don't
         # let it be clobbered by successive '-p' calls.
         try:
             last_call[0] = shell.displayhook.prompt_count
             if not opts_prev:
                 last_call[1] = args
         except:
             pass
 
 
         return filename, lineno, use_temp
 
     def _edit_macro(self,mname,macro):
         """open an editor with the macro data in a file"""
         filename = self.shell.mktempfile(macro.value)
         self.shell.hooks.editor(filename)
 
         # and make a new macro object, to replace the old one
         mvalue = Path(filename).read_text()
         self.shell.user_ns[mname] = Macro(mvalue)
 
     @skip_doctest
     @line_magic
     def edit(self, parameter_s='',last_call=['','']):
         """Bring up an editor and execute the resulting code.
 
         Usage:
           %edit [options] [args]
 
         %edit runs IPython's editor hook. The default version of this hook is
         set to call the editor specified by your $EDITOR environment variable.
         If this isn't found, it will default to vi under Linux/Unix and to
         notepad under Windows. See the end of this docstring for how to change
         the editor hook.
 
         You can also set the value of this editor via the
         ``TerminalInteractiveShell.editor`` option in your configuration file.
         This is useful if you wish to use a different editor from your typical
         default with IPython (and for Windows users who typically don't set
         environment variables).
 
         This command allows you to conveniently edit multi-line code right in
         your IPython session.
 
         If called without arguments, %edit opens up an empty editor with a
         temporary file and will execute the contents of this file when you
         close it (don't forget to save it!).
 
 
         Options:
 
         -n <number>: open the editor at a specified line number.  By default,
         the IPython editor hook uses the unix syntax 'editor +N filename', but
         you can configure this by providing your own modified hook if your
         favorite editor supports line-number specifications with a different
         syntax.
 
         -p: this will call the editor with the same data as the previous time
         it was used, regardless of how long ago (in your current session) it
         was.
 
         -r: use 'raw' input.  This option only applies to input taken from the
         user's history.  By default, the 'processed' history is used, so that
         magics are loaded in their transformed version to valid Python.  If
         this option is given, the raw input as typed as the command line is
         used instead.  When you exit the editor, it will be executed by
         IPython's own processor.
 
         -x: do not execute the edited code immediately upon exit. This is
         mainly useful if you are editing programs which need to be called with
         command line arguments, which you can then do using %run.
 
 
         Arguments:
 
         If arguments are given, the following possibilities exist:
 
         - If the argument is a filename, IPython will load that into the
           editor. It will execute its contents with execfile() when you exit,
           loading any code in the file into your interactive namespace.
 
         - The arguments are ranges of input history,  e.g. "7 ~1/4-6".
           The syntax is the same as in the %history magic.
 
         - If the argument is a string variable, its contents are loaded
           into the editor. You can thus edit any string which contains
           python code (including the result of previous edits).
 
         - If the argument is the name of an object (other than a string),
           IPython will try to locate the file where it was defined and open the
           editor at the point where it is defined. You can use `%edit function`
           to load an editor exactly at the point where 'function' is defined,
           edit it and have the file be executed automatically.
 
         - If the object is a macro (see %macro for details), this opens up your
           specified editor with a temporary file containing the macro's data.
           Upon exit, the macro is reloaded with the contents of the file.
 
         Note: opening at an exact line is only supported under Unix, and some
         editors (like kedit and gedit up to Gnome 2.8) do not understand the
         '+NUMBER' parameter necessary for this feature. Good editors like
         (X)Emacs, vi, jed, pico and joe all do.
 
         After executing your code, %edit will return as output the code you
         typed in the editor (except when it was an existing file). This way
         you can reload the code in further invocations of %edit as a variable,
         via _<NUMBER> or Out[<NUMBER>], where <NUMBER> is the prompt number of
         the output.
 
         Note that %edit is also available through the alias %ed.
 
         This is an example of creating a simple function inside the editor and
         then modifying it. First, start up the editor::
 
           In [1]: edit
           Editing... done. Executing edited code...
           Out[1]: 'def foo():\\n    print "foo() was defined in an editing
           session"\\n'
 
         We can then call the function foo()::
 
           In [2]: foo()
           foo() was defined in an editing session
 
         Now we edit foo.  IPython automatically loads the editor with the
         (temporary) file where foo() was previously defined::
 
           In [3]: edit foo
           Editing... done. Executing edited code...
 
         And if we call foo() again we get the modified version::
 
           In [4]: foo()
           foo() has now been changed!
 
         Here is an example of how to edit a code snippet successive
         times. First we call the editor::
 
           In [5]: edit
           Editing... done. Executing edited code...
           hello
           Out[5]: "print 'hello'\\n"
 
         Now we call it again with the previous output (stored in _)::
 
           In [6]: edit _
           Editing... done. Executing edited code...
           hello world
           Out[6]: "print 'hello world'\\n"
 
         Now we call it with the output #8 (stored in _8, also as Out[8])::
 
           In [7]: edit _8
           Editing... done. Executing edited code...
           hello again
           Out[7]: "print 'hello again'\\n"
 
 
         Changing the default editor hook:
 
         If you wish to write your own editor hook, you can put it in a
         configuration file which you load at startup time.  The default hook
         is defined in the IPython.core.hooks module, and you can use that as a
         starting example for further modifications.  That file also has
         general instructions on how to set a new hook for use once you've
         defined it."""
         opts,args = self.parse_options(parameter_s,'prxn:')
 
         try:
             filename, lineno, is_temp = self._find_edit_target(self.shell, 
                                                        args, opts, last_call)
         except MacroToEdit as e:
             self._edit_macro(args, e.args[0])
             return
         except InteractivelyDefined as e:
             print("Editing In[%i]" % e.index)
             args = str(e.index)
             filename, lineno, is_temp = self._find_edit_target(self.shell, 
                                                        args, opts, last_call)
         if filename is None:
             # nothing was found, warnings have already been issued,
             # just give up.
             return
 
         if is_temp:
             self._knowntemps.add(filename)
         elif (filename in self._knowntemps):
             is_temp = True
 
 
         # do actual editing here
         print('Editing...', end=' ')
         sys.stdout.flush()
         filepath = Path(filename)
         try:
             # Quote filenames that may have spaces in them when opening
             # the editor
             quoted = filename = str(filepath.absolute())
             if " " in quoted:
                 quoted = "'%s'" % quoted
             self.shell.hooks.editor(quoted, lineno)
         except TryNext:
             warn('Could not open editor')
             return
 
         # XXX TODO: should this be generalized for all string vars?
         # For now, this is special-cased to blocks created by cpaste
         if args.strip() == "pasted_block":
             self.shell.user_ns["pasted_block"] = filepath.read_text()
 
         if 'x' in opts:  # -x prevents actual execution
             print()
         else:
             print('done. Executing edited code...')
             with preserve_keys(self.shell.user_ns, '__file__'):
                 if not is_temp:
                     self.shell.user_ns['__file__'] = filename
                 if 'r' in opts:    # Untranslated IPython code
                     source = filepath.read_text()
                     self.shell.run_cell(source, store_history=False)
                 else:
                     self.shell.safe_execfile(filename, self.shell.user_ns,
                                              self.shell.user_ns)
 
         if is_temp:
             try:
                 return filepath.read_text()
             except IOError as msg:
                 if Path(msg.filename) == filepath:
                     warn('File not found. Did you forget to save?')
                     return
                 else:
                     self.shell.showtraceback()

IPython/core/magics/history.py

@@ -1,335 +1,333 b''
 """Implementation of magic functions related to History.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (c) 2012, IPython Development Team.
 #
 #  Distributed under the terms of the Modified BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Stdlib
 import os
 import sys
 from io import open as io_open
 import fnmatch
 
 # Our own packages
 from IPython.core.error import StdinNotImplementedError
 from IPython.core.magic import Magics, magics_class, line_magic
 from IPython.core.magic_arguments import (argument, magic_arguments,
                                           parse_argstring)
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import io
 
 #-----------------------------------------------------------------------------
 # Magics class implementation
 #-----------------------------------------------------------------------------
 
 
 _unspecified = object()
 
 
 @magics_class
 class HistoryMagics(Magics):
 
     @magic_arguments()
     @argument(
         '-n', dest='print_nums', action='store_true', default=False,
         help="""
         print line numbers for each input.
         This feature is only available if numbered prompts are in use.
         """)
     @argument(
         '-o', dest='get_output', action='store_true', default=False,
         help="also print outputs for each input.")
     @argument(
         '-p', dest='pyprompts', action='store_true', default=False,
         help="""
         print classic '>>>' python prompts before each input.
         This is useful for making documentation, and in conjunction
         with -o, for producing doctest-ready output.
         """)
     @argument(
         '-t', dest='raw', action='store_false', default=True,
         help="""
         print the 'translated' history, as IPython understands it.
         IPython filters your input and converts it all into valid Python
         source before executing it (things like magics or aliases are turned
         into function calls, for example). With this option, you'll see the
         native history instead of the user-entered version: '%%cd /' will be
         seen as 'get_ipython().run_line_magic("cd", "/")' instead of '%%cd /'.
         """)
     @argument(
         '-f', dest='filename',
         help="""
         FILENAME: instead of printing the output to the screen, redirect
         it to the given file.  The file is always overwritten, though *when
         it can*, IPython asks for confirmation first. In particular, running
         the command 'history -f FILENAME' from the IPython Notebook
         interface will replace FILENAME even if it already exists *without*
         confirmation.
         """)
     @argument(
         '-g', dest='pattern', nargs='*', default=None,
         help="""
         treat the arg as a glob pattern to search for in (full) history.
         This includes the saved history (almost all commands ever written).
         The pattern may contain '?' to match one unknown character and '*'
         to match any number of unknown characters. Use '%%hist -g' to show
         full saved history (may be very long).
         """)
     @argument(
         '-l', dest='limit', type=int, nargs='?', default=_unspecified,
         help="""
         get the last n lines from all sessions. Specify n as a single
         arg, or the default is the last 10 lines.
         """)
     @argument(
         '-u', dest='unique', action='store_true',
         help="""
         when searching history using `-g`, show only unique history.
         """)
     @argument('range', nargs='*')
     @skip_doctest
     @line_magic
     def history(self, parameter_s = ''):
         """Print input history (_i<n> variables), with most recent last.
 
         By default, input history is printed without line numbers so it can be
         directly pasted into an editor. Use -n to show them.
 
         By default, all input history from the current session is displayed.
         Ranges of history can be indicated using the syntax:
         
         ``4``
             Line 4, current session
         ``4-6``
             Lines 4-6, current session
         ``243/1-5``
             Lines 1-5, session 243
         ``~2/7``
             Line 7, session 2 before current
         ``~8/1-~6/5``
             From the first line of 8 sessions ago, to the fifth line of 6
             sessions ago.
         
         Multiple ranges can be entered, separated by spaces
 
         The same syntax is used by %macro, %save, %edit, %rerun
 
         Examples
         --------
         ::
 
           In [6]: %history -n 4-6
           4:a = 12
           5:print a**2
           6:%history -n 4-6
 
         """
 
         args = parse_argstring(self.history, parameter_s)
 
         # For brevity
         history_manager = self.shell.history_manager
 
         def _format_lineno(session, line):
             """Helper function to format line numbers properly."""
             if session in (0, history_manager.session_number):
                 return str(line)
             return "%s/%s" % (session, line)
 
         # Check if output to specific file was requested.
         outfname = args.filename
         if not outfname:
             outfile = sys.stdout  # default
             # We don't want to close stdout at the end!
             close_at_end = False
         else:
             if os.path.exists(outfname):
                 try:
                     ans = io.ask_yes_no("File %r exists. Overwrite?" % outfname)
                 except StdinNotImplementedError:
                     ans = True
                 if not ans:
                     print('Aborting.')
                     return
                 print("Overwriting file.")
             outfile = io_open(outfname, 'w', encoding='utf-8')
             close_at_end = True
 
         print_nums = args.print_nums
         get_output = args.get_output
         pyprompts = args.pyprompts
         raw = args.raw
 
         pattern = None
         limit = None if args.limit is _unspecified else args.limit
 
         range_pattern = False
         if args.pattern is not None and not args.range:
             if args.pattern:
                 pattern = "*" + " ".join(args.pattern) + "*"
             else:
                 pattern = "*"
             hist = history_manager.search(pattern, raw=raw, output=get_output,
                                           n=limit, unique=args.unique)
             print_nums = True
         elif args.limit is not _unspecified:
             n = 10 if limit is None else limit
             hist = history_manager.get_tail(n, raw=raw, output=get_output)
         else:
-            if args.range:      # Get history by ranges
-                if args.pattern:
-                    range_pattern = "*" + " ".join(args.pattern) + "*"
-                    print_nums = True
-                hist = history_manager.get_range_by_str(" ".join(args.range),
-                                                        raw, get_output)
-            else:               # Just get history for the current session
-                hist = history_manager.get_range(raw=raw, output=get_output)
+            if args.pattern:
+                range_pattern = "*" + " ".join(args.pattern) + "*"
+                print_nums = True
+            hist = history_manager.get_range_by_str(
+                " ".join(args.range), raw, get_output
+            )
 
         # We could be displaying the entire history, so let's not try to pull
         # it into a list in memory. Anything that needs more space will just
         # misalign.
         width = 4
 
         for session, lineno, inline in hist:
             # Print user history with tabs expanded to 4 spaces.  The GUI
             # clients use hard tabs for easier usability in auto-indented code,
             # but we want to produce PEP-8 compliant history for safe pasting
             # into an editor.
             if get_output:
                 inline, output = inline
             if range_pattern:
                 if not fnmatch.fnmatch(inline, range_pattern):
                     continue
             inline = inline.expandtabs(4).rstrip()
 
             multiline = "\n" in inline
             line_sep = '\n' if multiline else ' '
             if print_nums:
                 print(u'%s:%s' % (_format_lineno(session, lineno).rjust(width),
                         line_sep),  file=outfile, end=u'')
             if pyprompts:
                 print(u">>> ", end=u"", file=outfile)
                 if multiline:
                     inline = "\n... ".join(inline.splitlines()) + "\n..."
             print(inline, file=outfile)
             if get_output and output:
                 print(output, file=outfile)
 
         if close_at_end:
             outfile.close()
 
     @line_magic
     def recall(self, arg):
         r"""Repeat a command, or get command to input line for editing.
 
         %recall and %rep are equivalent.
 
         - %recall (no arguments):
 
         Place a string version of last computation result (stored in the
         special '_' variable) to the next input prompt. Allows you to create
         elaborate command lines without using copy-paste::
 
              In[1]: l = ["hei", "vaan"]
              In[2]: "".join(l)
             Out[2]: heivaan
              In[3]: %recall
              In[4]: heivaan_ <== cursor blinking
 
         %recall 45
 
         Place history line 45 on the next input prompt. Use %hist to find
         out the number.
 
         %recall 1-4
 
         Combine the specified lines into one cell, and place it on the next
         input prompt. See %history for the slice syntax.
 
         %recall foo+bar
 
         If foo+bar can be evaluated in the user namespace, the result is
         placed at the next input prompt. Otherwise, the history is searched
         for lines which contain that substring, and the most recent one is
         placed at the next input prompt.
         """
         if not arg:                 # Last output
             self.shell.set_next_input(str(self.shell.user_ns["_"]))
             return
                                     # Get history range
         histlines = self.shell.history_manager.get_range_by_str(arg)
         cmd = "\n".join(x[2] for x in histlines)
         if cmd:
             self.shell.set_next_input(cmd.rstrip())
             return
 
         try:                        # Variable in user namespace
             cmd = str(eval(arg, self.shell.user_ns))
         except Exception:           # Search for term in history
             histlines = self.shell.history_manager.search("*"+arg+"*")
             for h in reversed([x[2] for x in histlines]):
                 if 'recall' in h or 'rep' in h:
                     continue
                 self.shell.set_next_input(h.rstrip())
                 return
         else:
             self.shell.set_next_input(cmd.rstrip())
             return
         print("Couldn't evaluate or find in history:", arg)
 
     @line_magic
     def rerun(self, parameter_s=''):
         """Re-run previous input
 
         By default, you can specify ranges of input history to be repeated
         (as with %history). With no arguments, it will repeat the last line.
 
         Options:
 
           -l <n> : Repeat the last n lines of input, not including the
           current command.
 
           -g foo : Repeat the most recent line which contains foo
         """
         opts, args = self.parse_options(parameter_s, 'l:g:', mode='string')
         if "l" in opts:         # Last n lines
             n = int(opts['l'])
 
             if n == 0:
                 print("Requested 0 last lines - nothing to run")
                 return
             elif n < 0:
                 print("Number of lines to rerun cannot be negative")
                 return
 
             hist = self.shell.history_manager.get_tail(n)
         elif "g" in opts:       # Search
             p = "*"+opts['g']+"*"
             hist = list(self.shell.history_manager.search(p))
             for l in reversed(hist):
                 if "rerun" not in l[2]:
                     hist = [l]     # The last match which isn't a %rerun
                     break
             else:
                 hist = []          # No matches except %rerun
         elif args:              # Specify history ranges
             hist = self.shell.history_manager.get_range_by_str(args)
         else:                   # Last line
             hist = self.shell.history_manager.get_tail(1)
         hist = [x[2] for x in hist]
         if not hist:
             print("No lines in history match specification")
             return
         histlines = "\n".join(hist)
         print("=== Executing: ===")
         print(histlines)
         print("=== Output: ===")
         self.shell.run_cell("\n".join(hist), store_history=False)

IPython/core/magics/osm.py

@@ -1,860 +1,859 b''
 """Implementation of magic functions for interaction with the OS.
 
 Note: this module is named 'osm' instead of 'os' to avoid a collision with the
 builtin.
 """
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import io
 import os
 import re
 import sys
 from pprint import pformat
 
 from IPython.core import magic_arguments
 from IPython.core import oinspect
 from IPython.core import page
 from IPython.core.alias import AliasError, Alias
 from IPython.core.error import UsageError
 from IPython.core.magic import  (
     Magics, compress_dhist, magics_class, line_magic, cell_magic, line_cell_magic
 )
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils.openpy import source_to_unicode
 from IPython.utils.process import abbrev_cwd
 from IPython.utils.terminal import set_term_title
 from traitlets import Bool
 from warnings import warn
 
 
 @magics_class
 class OSMagics(Magics):
     """Magics to interact with the underlying OS (shell-type functionality).
     """
 
     cd_force_quiet = Bool(False,
         help="Force %cd magic to be quiet even if -q is not passed."
     ).tag(config=True)
 
     def __init__(self, shell=None, **kwargs):
 
         # Now define isexec in a cross platform manner.
         self.is_posix = False
         self.execre = None
         if os.name == 'posix':
             self.is_posix = True
         else:
             try:
                 winext = os.environ['pathext'].replace(';','|').replace('.','')
             except KeyError:
                 winext = 'exe|com|bat|py'
             try:
                 self.execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
             except re.error:
                 warn("Seems like your pathext environmental "
                      "variable is malformed. Please check it to "
                      "enable a proper handle of file extensions "
                      "managed for your system")
                 winext = 'exe|com|bat|py'
                 self.execre = re.compile(r'(.*)\.(%s)$' % winext,re.IGNORECASE)
 
         # call up the chain
         super().__init__(shell=shell, **kwargs)
 
 
     @skip_doctest
     def _isexec_POSIX(self, file):
         """
             Test for executable on a POSIX system
         """
         if os.access(file.path, os.X_OK):
             # will fail on maxOS if access is not X_OK
             return file.is_file()
         return False
 
 
     
     @skip_doctest
     def _isexec_WIN(self, file):
         """
             Test for executable file on non POSIX system
         """
         return file.is_file() and self.execre.match(file.name) is not None
 
     @skip_doctest
     def isexec(self, file):
         """
             Test for executable file on non POSIX system
         """
         if self.is_posix:
             return self._isexec_POSIX(file)
         else:
             return self._isexec_WIN(file)
 
 
     @skip_doctest
     @line_magic
     def alias(self, parameter_s=''):
         """Define an alias for a system command.
 
         '%alias alias_name cmd' defines 'alias_name' as an alias for 'cmd'
 
         Then, typing 'alias_name params' will execute the system command 'cmd
         params' (from your underlying operating system).
 
         Aliases have lower precedence than magic functions and Python normal
         variables, so if 'foo' is both a Python variable and an alias, the
         alias can not be executed until 'del foo' removes the Python variable.
 
         You can use the %l specifier in an alias definition to represent the
         whole line when the alias is called.  For example::
 
           In [2]: alias bracket echo "Input in brackets: <%l>"
           In [3]: bracket hello world
           Input in brackets: <hello world>
 
         You can also define aliases with parameters using %s specifiers (one
         per parameter)::
 
           In [1]: alias parts echo first %s second %s
           In [2]: %parts A B
           first A second B
           In [3]: %parts A
           Incorrect number of arguments: 2 expected.
           parts is an alias to: 'echo first %s second %s'
 
         Note that %l and %s are mutually exclusive.  You can only use one or
         the other in your aliases.
 
         Aliases expand Python variables just like system calls using ! or !!
         do: all expressions prefixed with '$' get expanded.  For details of
         the semantic rules, see PEP-215:
         http://www.python.org/peps/pep-0215.html.  This is the library used by
         IPython for variable expansion.  If you want to access a true shell
         variable, an extra $ is necessary to prevent its expansion by
         IPython::
 
           In [6]: alias show echo
           In [7]: PATH='A Python string'
           In [8]: show $PATH
           A Python string
           In [9]: show $$PATH
           /usr/local/lf9560/bin:/usr/local/intel/compiler70/ia32/bin:...
 
         You can use the alias facility to access all of $PATH.  See the %rehashx
         function, which automatically creates aliases for the contents of your
         $PATH.
 
         If called with no parameters, %alias prints the current alias table
         for your system.  For posix systems, the default aliases are 'cat',
         'cp', 'mv', 'rm', 'rmdir', and 'mkdir', and other platform-specific
         aliases are added.  For windows-based systems, the default aliases are
         'copy', 'ddir', 'echo', 'ls', 'ldir', 'mkdir', 'ren', and 'rmdir'.
 
         You can see the definition of alias by adding a question mark in the
         end::
 
           In [1]: cat?
           Repr: <alias cat for 'cat'>"""
 
         par = parameter_s.strip()
         if not par:
             aliases = sorted(self.shell.alias_manager.aliases)
             # stored = self.shell.db.get('stored_aliases', {} )
             # for k, v in stored:
             #     atab.append(k, v[0])
 
             print("Total number of aliases:", len(aliases))
             sys.stdout.flush()
             return aliases
 
         # Now try to define a new one
         try:
             alias,cmd = par.split(None, 1)
         except TypeError:
             print(oinspect.getdoc(self.alias))
             return
         
         try:
             self.shell.alias_manager.define_alias(alias, cmd)
         except AliasError as e:
             print(e)
     # end magic_alias
 
     @line_magic
     def unalias(self, parameter_s=''):
         """Remove an alias"""
 
         aname = parameter_s.strip()
         try:
             self.shell.alias_manager.undefine_alias(aname)
         except ValueError as e:
             print(e)
             return
         
         stored = self.shell.db.get('stored_aliases', {} )
         if aname in stored:
             print("Removing %stored alias",aname)
             del stored[aname]
             self.shell.db['stored_aliases'] = stored
 
     @line_magic
     def rehashx(self, parameter_s=''):
         """Update the alias table with all executable files in $PATH.
 
         rehashx explicitly checks that every entry in $PATH is a file
         with execute access (os.X_OK).
 
         Under Windows, it checks executability as a match against a
         '|'-separated string of extensions, stored in the IPython config
         variable win_exec_ext.  This defaults to 'exe|com|bat'.
 
         This function also resets the root module cache of module completer,
         used on slow filesystems.
         """
         from IPython.core.alias import InvalidAliasError
 
         # for the benefit of module completer in ipy_completers.py
         del self.shell.db['rootmodules_cache']
 
         path = [os.path.abspath(os.path.expanduser(p)) for p in
             os.environ.get('PATH','').split(os.pathsep)]
 
         syscmdlist = []
         savedir = os.getcwd()
 
         # Now walk the paths looking for executables to alias.
         try:
             # write the whole loop for posix/Windows so we don't have an if in
             # the innermost part
             if self.is_posix:
                 for pdir in path:
                     try:
                         os.chdir(pdir)
                     except OSError:
                         continue
 
                     # for python 3.6+ rewrite to: with os.scandir(pdir) as dirlist:
                     dirlist = os.scandir(path=pdir)
                     for ff in dirlist:
                         if self.isexec(ff):
                             fname = ff.name
                             try:
                                 # Removes dots from the name since ipython
                                 # will assume names with dots to be python.
                                 if not self.shell.alias_manager.is_alias(fname):
                                     self.shell.alias_manager.define_alias(
                                         fname.replace('.',''), fname)
                             except InvalidAliasError:
                                 pass
                             else:
                                 syscmdlist.append(fname)
             else:
                 no_alias = Alias.blacklist
                 for pdir in path:
                     try:
                         os.chdir(pdir)
                     except OSError:
                         continue
 
                     # for python 3.6+ rewrite to: with os.scandir(pdir) as dirlist:
                     dirlist = os.scandir(pdir)
                     for ff in dirlist:
                         fname = ff.name
                         base, ext = os.path.splitext(fname)
                         if self.isexec(ff) and base.lower() not in no_alias:
                             if ext.lower() == '.exe':
                                 fname = base
                                 try:
                                     # Removes dots from the name since ipython
                                     # will assume names with dots to be python.
                                     self.shell.alias_manager.define_alias(
                                         base.lower().replace('.',''), fname)
                                 except InvalidAliasError:
                                     pass
                                 syscmdlist.append(fname)
 
             self.shell.db['syscmdlist'] = syscmdlist
         finally:
             os.chdir(savedir)
 
     @skip_doctest
     @line_magic
     def pwd(self, parameter_s=''):
         """Return the current working directory path.
 
         Examples
         --------
         ::
 
           In [9]: pwd
           Out[9]: '/home/tsuser/sprint/ipython'
         """
         try:
             return os.getcwd()
         except FileNotFoundError as e:
             raise UsageError("CWD no longer exists - please use %cd to change directory.") from e
 
     @skip_doctest
     @line_magic
     def cd(self, parameter_s=''):
         """Change the current working directory.
 
         This command automatically maintains an internal list of directories
         you visit during your IPython session, in the variable ``_dh``. The
         command :magic:`%dhist` shows this history nicely formatted. You can
         also do ``cd -<tab>`` to see directory history conveniently.
         Usage:
 
           - ``cd 'dir'``: changes to directory 'dir'.
           - ``cd -``: changes to the last visited directory.
           - ``cd -<n>``: changes to the n-th directory in the directory history.
           - ``cd --foo``: change to directory that matches 'foo' in history
           - ``cd -b <bookmark_name>``: jump to a bookmark set by %bookmark
           - Hitting a tab key after ``cd -b`` allows you to tab-complete
             bookmark names.
 
           .. note::
             ``cd <bookmark_name>`` is enough if there is no directory
             ``<bookmark_name>``, but a bookmark with the name exists.
 
 
         Options:
 
         -q               Be quiet. Do not print the working directory after the
                          cd command is executed. By default IPython's cd
                          command does print this directory, since the default
                          prompts do not display path information.
 
         .. note::
            Note that ``!cd`` doesn't work for this purpose because the shell
            where ``!command`` runs is immediately discarded after executing
            'command'.
 
 
         Examples
         --------
         ::
 
           In [10]: cd parent/child
           /home/tsuser/parent/child
         """
 
         try:
             oldcwd = os.getcwd()
         except FileNotFoundError:
             # Happens if the CWD has been deleted.
             oldcwd = None
 
         numcd = re.match(r'(-)(\d+)$',parameter_s)
         # jump in directory history by number
         if numcd:
             nn = int(numcd.group(2))
             try:
                 ps = self.shell.user_ns['_dh'][nn]
             except IndexError:
                 print('The requested directory does not exist in history.')
                 return
             else:
                 opts = {}
         elif parameter_s.startswith('--'):
             ps = None
             fallback = None
             pat = parameter_s[2:]
             dh = self.shell.user_ns['_dh']
             # first search only by basename (last component)
             for ent in reversed(dh):
                 if pat in os.path.basename(ent) and os.path.isdir(ent):
                     ps = ent
                     break
 
                 if fallback is None and pat in ent and os.path.isdir(ent):
                     fallback = ent
 
             # if we have no last part match, pick the first full path match
             if ps is None:
                 ps = fallback
 
             if ps is None:
                 print("No matching entry in directory history")
                 return
             else:
                 opts = {}
 
 
         else:
             opts, ps = self.parse_options(parameter_s, 'qb', mode='string')
         # jump to previous
         if ps == '-':
             try:
                 ps = self.shell.user_ns['_dh'][-2]
             except IndexError as e:
                 raise UsageError('%cd -: No previous directory to change to.') from e
         # jump to bookmark if needed
         else:
             if not os.path.isdir(ps) or 'b' in opts:
                 bkms = self.shell.db.get('bookmarks', {})
 
                 if ps in bkms:
                     target = bkms[ps]
                     print('(bookmark:%s) -> %s' % (ps, target))
                     ps = target
                 else:
                     if 'b' in opts:
                         raise UsageError("Bookmark '%s' not found.  "
                               "Use '%%bookmark -l' to see your bookmarks." % ps)
 
         # at this point ps should point to the target dir
         if ps:
             try:
                 os.chdir(os.path.expanduser(ps))
                 if hasattr(self.shell, 'term_title') and self.shell.term_title:
                     set_term_title(self.shell.term_title_format.format(cwd=abbrev_cwd()))
             except OSError:
                 print(sys.exc_info()[1])
             else:
                 cwd = os.getcwd()
                 dhist = self.shell.user_ns['_dh']
                 if oldcwd != cwd:
                     dhist.append(cwd)
                     self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
 
         else:
             os.chdir(self.shell.home_dir)
             if hasattr(self.shell, 'term_title') and self.shell.term_title:
                 set_term_title(self.shell.term_title_format.format(cwd="~"))
             cwd = os.getcwd()
             dhist = self.shell.user_ns['_dh']
 
             if oldcwd != cwd:
                 dhist.append(cwd)
                 self.shell.db['dhist'] = compress_dhist(dhist)[-100:]
         if not 'q' in opts and not self.cd_force_quiet and self.shell.user_ns['_dh']:
             print(self.shell.user_ns['_dh'][-1])
 
     @line_magic
     def env(self, parameter_s=''):
         """Get, set, or list environment variables.
 
         Usage:\\
 
           :``%env``: lists all environment variables/values
           :``%env var``: get value for var
           :``%env var val``: set value for var
           :``%env var=val``: set value for var
           :``%env var=$val``: set value for var, using python expansion if possible
         """
         if parameter_s.strip():
             split = '=' if '=' in parameter_s else ' '
             bits = parameter_s.split(split)
             if len(bits) == 1:
                 key = parameter_s.strip()
                 if key in os.environ:
                     return os.environ[key]
                 else:
                     err = "Environment does not have key: {0}".format(key)
                     raise UsageError(err)
             if len(bits) > 1:
                 return self.set_env(parameter_s)
         env = dict(os.environ)
         # hide likely secrets when printing the whole environment
         for key in list(env):
             if any(s in key.lower() for s in ('key', 'token', 'secret')):
                 env[key] = '<hidden>'
 
         return env
 
     @line_magic
     def set_env(self, parameter_s):
         """Set environment variables.  Assumptions are that either "val" is a
         name in the user namespace, or val is something that evaluates to a
         string.
 
         Usage:\\
           %set_env var val: set value for var
           %set_env var=val: set value for var
           %set_env var=$val: set value for var, using python expansion if possible
         """
         split = '=' if '=' in parameter_s else ' '
         bits = parameter_s.split(split, 1)
         if not parameter_s.strip() or len(bits)<2:
             raise UsageError("usage is 'set_env var=val'")
         var = bits[0].strip()
         val = bits[1].strip()
         if re.match(r'.*\s.*', var):
             # an environment variable with whitespace is almost certainly
             # not what the user intended.  what's more likely is the wrong
             # split was chosen, ie for "set_env cmd_args A=B", we chose
             # '=' for the split and should have chosen ' '.  to get around
             # this, users should just assign directly to os.environ or use
             # standard magic {var} expansion.
             err = "refusing to set env var with whitespace: '{0}'"
             err = err.format(val)
             raise UsageError(err)
         os.environ[var] = val
         print('env: {0}={1}'.format(var,val))
 
     @line_magic
     def pushd(self, parameter_s=''):
         """Place the current dir on stack and change directory.
 
         Usage:\\
           %pushd ['dirname']
         """
 
         dir_s = self.shell.dir_stack
         tgt = os.path.expanduser(parameter_s)
         cwd = os.getcwd().replace(self.shell.home_dir,'~')
         if tgt:
             self.cd(parameter_s)
         dir_s.insert(0,cwd)
         return self.shell.run_line_magic('dirs', '')
 
     @line_magic
     def popd(self, parameter_s=''):
         """Change to directory popped off the top of the stack.
         """
         if not self.shell.dir_stack:
             raise UsageError("%popd on empty stack")
         top = self.shell.dir_stack.pop(0)
         self.cd(top)
         print("popd ->",top)
 
     @line_magic
     def dirs(self, parameter_s=''):
         """Return the current directory stack."""
 
         return self.shell.dir_stack
 
     @line_magic
     def dhist(self, parameter_s=''):
         """Print your history of visited directories.
 
         %dhist       -> print full history\\
         %dhist n     -> print last n entries only\\
         %dhist n1 n2 -> print entries between n1 and n2 (n2 not included)\\
 
         This history is automatically maintained by the %cd command, and
         always available as the global list variable _dh. You can use %cd -<n>
         to go to directory number <n>.
 
         Note that most of time, you should view directory history by entering
         cd -<TAB>.
 
         """
 
         dh = self.shell.user_ns['_dh']
         if parameter_s:
             try:
                 args = map(int,parameter_s.split())
             except:
                 self.arg_err(self.dhist)
                 return
             if len(args) == 1:
                 ini,fin = max(len(dh)-(args[0]),0),len(dh)
             elif len(args) == 2:
                 ini,fin = args
                 fin = min(fin, len(dh))
             else:
                 self.arg_err(self.dhist)
                 return
         else:
             ini,fin = 0,len(dh)
         print('Directory history (kept in _dh)')
         for i in range(ini, fin):
             print("%d: %s" % (i, dh[i]))
 
     @skip_doctest
     @line_magic
     def sc(self, parameter_s=''):
         """Shell capture - run shell command and capture output (DEPRECATED use !).
 
         DEPRECATED. Suboptimal, retained for backwards compatibility.
 
         You should use the form 'var = !command' instead. Example:
 
          "%sc -l myfiles = ls ~" should now be written as
 
          "myfiles = !ls ~"
 
         myfiles.s, myfiles.l and myfiles.n still apply as documented
         below.
 
         --
         %sc [options] varname=command
 
         IPython will run the given command using commands.getoutput(), and
         will then update the user's interactive namespace with a variable
         called varname, containing the value of the call.  Your command can
         contain shell wildcards, pipes, etc.
 
         The '=' sign in the syntax is mandatory, and the variable name you
         supply must follow Python's standard conventions for valid names.
 
         (A special format without variable name exists for internal use)
 
         Options:
 
           -l: list output.  Split the output on newlines into a list before
           assigning it to the given variable.  By default the output is stored
           as a single string.
 
           -v: verbose.  Print the contents of the variable.
 
         In most cases you should not need to split as a list, because the
         returned value is a special type of string which can automatically
         provide its contents either as a list (split on newlines) or as a
         space-separated string.  These are convenient, respectively, either
         for sequential processing or to be passed to a shell command.
 
         For example::
 
             # Capture into variable a
             In [1]: sc a=ls *py
 
             # a is a string with embedded newlines
             In [2]: a
             Out[2]: 'setup.py\\nwin32_manual_post_install.py'
 
             # which can be seen as a list:
             In [3]: a.l
             Out[3]: ['setup.py', 'win32_manual_post_install.py']
 
             # or as a whitespace-separated string:
             In [4]: a.s
             Out[4]: 'setup.py win32_manual_post_install.py'
 
             # a.s is useful to pass as a single command line:
             In [5]: !wc -l $a.s
               146 setup.py
               130 win32_manual_post_install.py
               276 total
 
             # while the list form is useful to loop over:
             In [6]: for f in a.l:
               ...:      !wc -l $f
               ...:
             146 setup.py
             130 win32_manual_post_install.py
 
         Similarly, the lists returned by the -l option are also special, in
         the sense that you can equally invoke the .s attribute on them to
         automatically get a whitespace-separated string from their contents::
 
             In [7]: sc -l b=ls *py
 
             In [8]: b
             Out[8]: ['setup.py', 'win32_manual_post_install.py']
 
             In [9]: b.s
             Out[9]: 'setup.py win32_manual_post_install.py'
 
         In summary, both the lists and strings used for output capture have
         the following special attributes::
 
             .l (or .list) : value as list.
             .n (or .nlstr): value as newline-separated string.
             .s (or .spstr): value as space-separated string.
         """
 
         opts,args = self.parse_options(parameter_s, 'lv')
         # Try to get a variable name and command to run
         try:
             # the variable name must be obtained from the parse_options
             # output, which uses shlex.split to strip options out.
             var,_ = args.split('=', 1)
             var = var.strip()
             # But the command has to be extracted from the original input
             # parameter_s, not on what parse_options returns, to avoid the
             # quote stripping which shlex.split performs on it.
             _,cmd = parameter_s.split('=', 1)
         except ValueError:
             var,cmd = '',''
         # If all looks ok, proceed
         split = 'l' in opts
         out = self.shell.getoutput(cmd, split=split)
         if 'v' in opts:
             print('%s ==\n%s' % (var, pformat(out)))
         if var:
             self.shell.user_ns.update({var:out})
         else:
             return out
 
     @line_cell_magic
     def sx(self, line='', cell=None):
         """Shell execute - run shell command and capture output (!! is short-hand).
 
         %sx command
 
         IPython will run the given command using commands.getoutput(), and
         return the result formatted as a list (split on '\\n').  Since the
         output is _returned_, it will be stored in ipython's regular output
         cache Out[N] and in the '_N' automatic variables.
 
         Notes:
 
         1) If an input line begins with '!!', then %sx is automatically
         invoked.  That is, while::
 
           !ls
 
         causes ipython to simply issue system('ls'), typing::
 
           !!ls
 
         is a shorthand equivalent to::
 
           %sx ls
 
         2) %sx differs from %sc in that %sx automatically splits into a list,
         like '%sc -l'.  The reason for this is to make it as easy as possible
         to process line-oriented shell output via further python commands.
         %sc is meant to provide much finer control, but requires more
         typing.
 
         3) Just like %sc -l, this is a list with special attributes:
         ::
 
           .l (or .list) : value as list.
           .n (or .nlstr): value as newline-separated string.
           .s (or .spstr): value as whitespace-separated string.
 
         This is very useful when trying to use such lists as arguments to
         system commands."""
         
         if cell is None:
             # line magic
             return self.shell.getoutput(line)
         else:
             opts,args = self.parse_options(line, '', 'out=')
             output = self.shell.getoutput(cell)
             out_name = opts.get('out', opts.get('o'))
             if out_name:
                 self.shell.user_ns[out_name] = output
             else:
                 return output
 
     system = line_cell_magic('system')(sx)
     bang = cell_magic('!')(sx)
 
     @line_magic
     def bookmark(self, parameter_s=''):
         """Manage IPython's bookmark system.
 
         %bookmark <name>       - set bookmark to current dir
         %bookmark <name> <dir> - set bookmark to <dir>
         %bookmark -l           - list all bookmarks
         %bookmark -d <name>    - remove bookmark
         %bookmark -r           - remove all bookmarks
 
         You can later on access a bookmarked folder with::
 
           %cd -b <name>
 
         or simply '%cd <name>' if there is no directory called <name> AND
         there is such a bookmark defined.
 
         Your bookmarks persist through IPython sessions, but they are
         associated with each profile."""
 
         opts,args = self.parse_options(parameter_s,'drl',mode='list')
         if len(args) > 2:
             raise UsageError("%bookmark: too many arguments")
 
         bkms = self.shell.db.get('bookmarks',{})
 
         if 'd' in opts:
             try:
                 todel = args[0]
             except IndexError as e:
                 raise UsageError(
                     "%bookmark -d: must provide a bookmark to delete") from e
             else:
                 try:
                     del bkms[todel]
                 except KeyError as e:
                     raise UsageError(
                         "%%bookmark -d: Can't delete bookmark '%s'" % todel) from e
 
         elif 'r' in opts:
             bkms = {}
         elif 'l' in opts:
             bks = sorted(bkms)
             if bks:
                 size = max(map(len, bks))
             else:
                 size = 0
             fmt = '%-'+str(size)+'s -> %s'
             print('Current bookmarks:')
             for bk in bks:
                 print(fmt % (bk, bkms[bk]))
         else:
             if not args:
                 raise UsageError("%bookmark: You must specify the bookmark name")
             elif len(args)==1:
                 bkms[args[0]] = os.getcwd()
             elif len(args)==2:
                 bkms[args[0]] = args[1]
         self.shell.db['bookmarks'] = bkms
 
     @line_magic
     def pycat(self, parameter_s=''):
         """Show a syntax-highlighted file through a pager.
 
         This magic is similar to the cat utility, but it will assume the file
         to be Python source and will show it with syntax highlighting.
 
         This magic command can either take a local filename, an url,
-        an history range (see %history) or a macro as argument ::
+        an history range (see %history) or a macro as argument.
+
+        If no parameter is given, prints out history of current session up to
+        this point. ::
 
         %pycat myscript.py
         %pycat 7-27
         %pycat myMacro
         %pycat http://www.example.com/myscript.py
         """
-        if not parameter_s:
-            raise UsageError('Missing filename, URL, input history range, '
-                             'or macro.')
-
-        try :
+        try:
             cont = self.shell.find_user_code(parameter_s, skip_encoding_cookie=False)
         except (ValueError, IOError):
             print("Error: no such file, variable, URL, history range or macro")
             return
 
         page.page(self.shell.pycolorize(source_to_unicode(cont)))
 
     @magic_arguments.magic_arguments()
     @magic_arguments.argument(
         '-a', '--append', action='store_true', default=False,
         help='Append contents of the cell to an existing file. '
              'The file will be created if it does not exist.'
     )
     @magic_arguments.argument(
         'filename', type=str,
         help='file to write'
     )
     @cell_magic
     def writefile(self, line, cell):
         """Write the contents of the cell to a file.
         
         The file will be overwritten unless the -a (--append) flag is specified.
         """
         args = magic_arguments.parse_argstring(self.writefile, line)
         if re.match(r'^(\'.*\')|(".*")$', args.filename):
             filename = os.path.expanduser(args.filename[1:-1])
         else:
             filename = os.path.expanduser(args.filename)
             
         if os.path.exists(filename):
             if args.append:
                 print("Appending to %s" % filename)
             else:
                 print("Overwriting %s" % filename)
         else:
             print("Writing %s" % filename)
         
         mode = 'a' if args.append else 'w'
         with io.open(filename, mode, encoding='utf-8') as f:
             f.write(cell)

IPython/core/tests/test_history.py

@@ -1,215 +1,223 b''
 # coding: utf-8
 """Tests for the IPython tab-completion machinery.
 """
 #-----------------------------------------------------------------------------
 # Module imports
 #-----------------------------------------------------------------------------
 
 # stdlib
 import io
 from pathlib import Path
 import sys
 import tempfile
 from datetime import datetime
 import sqlite3
 
 # third party
 import nose.tools as nt
 
 # our own packages
 from traitlets.config.loader import Config
 from IPython.utils.tempdir import TemporaryDirectory
 from IPython.core.history import HistoryManager, extract_hist_ranges
 from IPython.testing.decorators import skipif
 
 def test_proper_default_encoding():
     nt.assert_equal(sys.getdefaultencoding(), "utf-8")
 
 @skipif(sqlite3.sqlite_version_info > (3,24,0))
 def test_history():
     ip = get_ipython()
     with TemporaryDirectory() as tmpdir:
         tmp_path = Path(tmpdir)
         hist_manager_ori = ip.history_manager
         hist_file = tmp_path / "history.sqlite"
         try:
             ip.history_manager = HistoryManager(shell=ip, hist_file=hist_file)
             hist = [u'a=1', u'def f():\n    test = 1\n    return test', u"b='€Æ¾÷ß'"]
             for i, h in enumerate(hist, start=1):
                 ip.history_manager.store_inputs(i, h)
 
             ip.history_manager.db_log_output = True
             # Doesn't match the input, but we'll just check it's stored.
             ip.history_manager.output_hist_reprs[3] = "spam"
             ip.history_manager.store_output(3)
 
             nt.assert_equal(ip.history_manager.input_hist_raw, [''] + hist)
 
             # Detailed tests for _get_range_session
             grs = ip.history_manager._get_range_session
             nt.assert_equal(list(grs(start=2,stop=-1)), list(zip([0], [2], hist[1:-1])))
             nt.assert_equal(list(grs(start=-2)), list(zip([0,0], [2,3], hist[-2:])))
             nt.assert_equal(list(grs(output=True)), list(zip([0,0,0], [1,2,3], zip(hist, [None,None,'spam']))))
 
             # Check whether specifying a range beyond the end of the current
             # session results in an error (gh-804)
             ip.magic('%hist 2-500')
 
             # Check that we can write non-ascii characters to a file
             ip.magic("%%hist -f %s" % (tmp_path / "test1"))
             ip.magic("%%hist -pf %s" % (tmp_path / "test2"))
             ip.magic("%%hist -nf %s" % (tmp_path / "test3"))
             ip.magic("%%save %s 1-10" % (tmp_path / "test4"))
 
             # New session
             ip.history_manager.reset()
             newcmds = [u"z=5",
                        u"class X(object):\n    pass",
                        u"k='p'",
                        u"z=5"]
             for i, cmd in enumerate(newcmds, start=1):
                 ip.history_manager.store_inputs(i, cmd)
             gothist = ip.history_manager.get_range(start=1, stop=4)
             nt.assert_equal(list(gothist), list(zip([0,0,0],[1,2,3], newcmds)))
             # Previous session:
             gothist = ip.history_manager.get_range(-1, 1, 4)
             nt.assert_equal(list(gothist), list(zip([1,1,1],[1,2,3], hist)))
 
             newhist = [(2, i, c) for (i, c) in enumerate(newcmds, 1)]
 
             # Check get_hist_tail
             gothist = ip.history_manager.get_tail(5, output=True,
                                                     include_latest=True)
             expected = [(1, 3, (hist[-1], "spam"))] \
                 + [(s, n, (c, None)) for (s, n, c) in newhist]
             nt.assert_equal(list(gothist), expected)
 
             gothist = ip.history_manager.get_tail(2)
             expected = newhist[-3:-1]
             nt.assert_equal(list(gothist), expected)
 
             # Check get_hist_search
 
             gothist = ip.history_manager.search("*test*")
             nt.assert_equal(list(gothist), [(1,2,hist[1])] )
 
             gothist = ip.history_manager.search("*=*")
             nt.assert_equal(list(gothist),
                             [(1, 1, hist[0]),
                              (1, 2, hist[1]),
                              (1, 3, hist[2]),
                              newhist[0],
                              newhist[2],
                              newhist[3]])
 
             gothist = ip.history_manager.search("*=*", n=4)
             nt.assert_equal(list(gothist),
                             [(1, 3, hist[2]),
                              newhist[0],
                              newhist[2],
                              newhist[3]])
 
             gothist = ip.history_manager.search("*=*", unique=True)
             nt.assert_equal(list(gothist),
                             [(1, 1, hist[0]),
                              (1, 2, hist[1]),
                              (1, 3, hist[2]),
                              newhist[2],
                              newhist[3]])
 
             gothist = ip.history_manager.search("*=*", unique=True, n=3)
             nt.assert_equal(list(gothist),
                             [(1, 3, hist[2]),
                              newhist[2],
                              newhist[3]])
 
             gothist = ip.history_manager.search("b*", output=True)
             nt.assert_equal(list(gothist), [(1,3,(hist[2],"spam"))] )
 
             # Cross testing: check that magic %save can get previous session.
             testfilename = (tmp_path / "test.py").resolve()
             ip.magic("save " + str(testfilename) + " ~1/1-3")
             with io.open(testfilename, encoding='utf-8') as testfile:
                 nt.assert_equal(testfile.read(),
                                         u"# coding: utf-8\n" + u"\n".join(hist)+u"\n")
 
             # Duplicate line numbers - check that it doesn't crash, and
             # gets a new session
             ip.history_manager.store_inputs(1, "rogue")
             ip.history_manager.writeout_cache()
             nt.assert_equal(ip.history_manager.session_number, 3)
         finally:
             # Ensure saving thread is shut down before we try to clean up the files
             ip.history_manager.save_thread.stop()
             # Forcibly close database rather than relying on garbage collection
             ip.history_manager.db.close()
             # Restore history manager
             ip.history_manager = hist_manager_ori
 
 
 def test_extract_hist_ranges():
     instr = "1 2/3 ~4/5-6 ~4/7-~4/9 ~9/2-~7/5 ~10/"
     expected = [(0, 1, 2),  # 0 == current session
                 (2, 3, 4),
                 (-4, 5, 7),
                 (-4, 7, 10),
                 (-9, 2, None),  # None == to end
                 (-8, 1, None),
                 (-7, 1, 6),
                 (-10, 1, None)]
     actual = list(extract_hist_ranges(instr))
     nt.assert_equal(actual, expected)
 
+
+def test_extract_hist_ranges_empty_str():
+    instr = ""
+    expected = [(0, 1, None)]  # 0 == current session, None == to end
+    actual = list(extract_hist_ranges(instr))
+    nt.assert_equal(actual, expected)
+
+
 def test_magic_rerun():
     """Simple test for %rerun (no args -> rerun last line)"""
     ip = get_ipython()
     ip.run_cell("a = 10", store_history=True)
     ip.run_cell("a += 1", store_history=True)
     nt.assert_equal(ip.user_ns["a"], 11)
     ip.run_cell("%rerun", store_history=True)
     nt.assert_equal(ip.user_ns["a"], 12)
 
 def test_timestamp_type():
     ip = get_ipython()
     info = ip.history_manager.get_session_info()
     nt.assert_true(isinstance(info[1], datetime))
 
 def test_hist_file_config():
     cfg = Config()
     tfile = tempfile.NamedTemporaryFile(delete=False)
     cfg.HistoryManager.hist_file = Path(tfile.name)
     try:
         hm = HistoryManager(shell=get_ipython(), config=cfg)
         nt.assert_equal(hm.hist_file, cfg.HistoryManager.hist_file)
     finally:
         try:
             Path(tfile.name).unlink()
         except OSError:
             # same catch as in testing.tools.TempFileMixin
             # On Windows, even though we close the file, we still can't
             # delete it.  I have no clue why
             pass
 
 def test_histmanager_disabled():
     """Ensure that disabling the history manager doesn't create a database."""
     cfg = Config()
     cfg.HistoryAccessor.enabled = False
 
     ip = get_ipython()
     with TemporaryDirectory() as tmpdir:
         hist_manager_ori = ip.history_manager
         hist_file = Path(tmpdir) / "history.sqlite"
         cfg.HistoryManager.hist_file = hist_file
         try:
             ip.history_manager = HistoryManager(shell=ip, config=cfg)
             hist = [u'a=1', u'def f():\n    test = 1\n    return test', u"b='€Æ¾÷ß'"]
             for i, h in enumerate(hist, start=1):
                 ip.history_manager.store_inputs(i, h)
             nt.assert_equal(ip.history_manager.input_hist_raw, [''] + hist)
             ip.history_manager.reset()
             ip.history_manager.end_session()
         finally:
             ip.history_manager = hist_manager_ori
 
     # hist_file should not be created
     nt.assert_false(hist_file.exists())

IPython/core/tests/test_magic.py

@@ -1,1279 +1,1302 b''
 # -*- coding: utf-8 -*-
 """Tests for various magic functions.
 
 Needs to be run by nose (to make ipython session available).
 """
 
 import io
 import os
 import re
 import sys
 import warnings
 from textwrap import dedent
 from unittest import TestCase
 from unittest import mock
 from importlib import invalidate_caches
 from io import StringIO
 from pathlib import Path
 
 import nose.tools as nt
 
 import shlex
 
 from IPython import get_ipython
 from IPython.core import magic
 from IPython.core.error import UsageError
 from IPython.core.magic import (Magics, magics_class, line_magic,
                                 cell_magic,
                                 register_line_magic, register_cell_magic)
 from IPython.core.magics import execution, script, code, logging, osm
 from IPython.testing import decorators as dec
 from IPython.testing import tools as tt
 from IPython.utils.io import capture_output
 from IPython.utils.tempdir import (TemporaryDirectory,
                                     TemporaryWorkingDirectory)
 from IPython.utils.process import find_cmd
 from .test_debugger import PdbTestInput
 
 import pytest
 
 
 @magic.magics_class
 class DummyMagics(magic.Magics): pass
 
 def test_extract_code_ranges():
     instr = "1 3 5-6 7-9 10:15 17: :10 10- -13 :"
     expected = [(0, 1), 
                 (2, 3),
                 (4, 6),
                 (6, 9),
                 (9, 14),
                 (16, None),
                 (None, 9),
                 (9, None),
                 (None, 13),
                 (None, None)]
     actual = list(code.extract_code_ranges(instr))
     nt.assert_equal(actual, expected)
 
 def test_extract_symbols():
     source = """import foo\na = 10\ndef b():\n    return 42\n\n\nclass A: pass\n\n\n"""
     symbols_args = ["a", "b", "A", "A,b", "A,a", "z"]
     expected = [([], ['a']),
                 (["def b():\n    return 42\n"], []),
                 (["class A: pass\n"], []),
                 (["class A: pass\n", "def b():\n    return 42\n"], []),
                 (["class A: pass\n"], ['a']),
                 ([], ['z'])]
     for symbols, exp in zip(symbols_args, expected):
         nt.assert_equal(code.extract_symbols(source, symbols), exp)
 
 
 def test_extract_symbols_raises_exception_with_non_python_code():
     source = ("=begin A Ruby program :)=end\n"
               "def hello\n"
               "puts 'Hello world'\n"
               "end")
     with nt.assert_raises(SyntaxError):
         code.extract_symbols(source, "hello")
 
 
 def test_magic_not_found():
     # magic not found raises UsageError
     with nt.assert_raises(UsageError):
         _ip.magic('doesntexist')
 
     # ensure result isn't success when a magic isn't found
     result = _ip.run_cell('%doesntexist')
     assert isinstance(result.error_in_exec, UsageError)
 
 
 def test_cell_magic_not_found():
     # magic not found raises UsageError
     with nt.assert_raises(UsageError):
         _ip.run_cell_magic('doesntexist', 'line', 'cell')
 
     # ensure result isn't success when a magic isn't found
     result = _ip.run_cell('%%doesntexist')
     assert isinstance(result.error_in_exec, UsageError)
 
 
 def test_magic_error_status():
     def fail(shell):
         1/0
     _ip.register_magic_function(fail)
     result = _ip.run_cell('%fail')
     assert isinstance(result.error_in_exec, ZeroDivisionError)
 
 
 def test_config():
     """ test that config magic does not raise
     can happen if Configurable init is moved too early into
     Magics.__init__ as then a Config object will be registered as a
     magic.
     """
     ## should not raise.
     _ip.magic('config')
 
 def test_config_available_configs():
     """ test that config magic prints available configs in unique and
     sorted order. """
     with capture_output() as captured:
         _ip.magic('config')
 
     stdout = captured.stdout
     config_classes = stdout.strip().split('\n')[1:]
     nt.assert_list_equal(config_classes, sorted(set(config_classes)))
 
 def test_config_print_class():
     """ test that config with a classname prints the class's options. """
     with capture_output() as captured:
         _ip.magic('config TerminalInteractiveShell')
 
     stdout = captured.stdout
     if not re.match("TerminalInteractiveShell.* options", stdout.splitlines()[0]):
         print(stdout)
         raise AssertionError("1st line of stdout not like "
                              "'TerminalInteractiveShell.* options'")
 
 def test_rehashx():
     # clear up everything
     _ip.alias_manager.clear_aliases()
     del _ip.db['syscmdlist']
     
     _ip.magic('rehashx')
     # Practically ALL ipython development systems will have more than 10 aliases
 
     nt.assert_true(len(_ip.alias_manager.aliases) > 10)
     for name, cmd in _ip.alias_manager.aliases:
         # we must strip dots from alias names
         nt.assert_not_in('.', name)
 
     # rehashx must fill up syscmdlist
     scoms = _ip.db['syscmdlist']
     nt.assert_true(len(scoms) > 10)
             
 
 
 def test_magic_parse_options():
     """Test that we don't mangle paths when parsing magic options."""
     ip = get_ipython()
     path = 'c:\\x'
     m = DummyMagics(ip)
     opts = m.parse_options('-f %s' % path,'f:')[0]
     # argv splitting is os-dependent
     if os.name == 'posix':
         expected = 'c:x'
     else:
         expected = path
     nt.assert_equal(opts['f'], expected)
 
 def test_magic_parse_long_options():
     """Magic.parse_options can handle --foo=bar long options"""
     ip = get_ipython()
     m = DummyMagics(ip)
     opts, _ = m.parse_options('--foo --bar=bubble', 'a', 'foo', 'bar=')
     nt.assert_in('foo', opts)
     nt.assert_in('bar', opts)
     nt.assert_equal(opts['bar'], "bubble")
 
 
 def doctest_hist_f():
     """Test %hist -f with temporary filename.
 
     In [9]: import tempfile
 
     In [10]: tfile = tempfile.mktemp('.py','tmp-ipython-')
 
     In [11]: %hist -nl -f $tfile 3
 
     In [13]: import os; os.unlink(tfile)
     """
 
 
 def doctest_hist_op():
     """Test %hist -op
 
     In [1]: class b(float):
        ...:     pass
        ...: 
 
     In [2]: class s(object):
        ...:     def __str__(self):
        ...:         return 's'
        ...: 
 
     In [3]: 
 
     In [4]: class r(b):
        ...:     def __repr__(self):
        ...:         return 'r'
        ...: 
 
     In [5]: class sr(s,r): pass
        ...: 
 
     In [6]: 
 
     In [7]: bb=b()
 
     In [8]: ss=s()
 
     In [9]: rr=r()
 
     In [10]: ssrr=sr()
 
     In [11]: 4.5
     Out[11]: 4.5
 
     In [12]: str(ss)
     Out[12]: 's'
 
     In [13]: 
 
     In [14]: %hist -op
     >>> class b:
     ...     pass
     ... 
     >>> class s(b):
     ...     def __str__(self):
     ...         return 's'
     ... 
     >>> 
     >>> class r(b):
     ...     def __repr__(self):
     ...         return 'r'
     ... 
     >>> class sr(s,r): pass
     >>> 
     >>> bb=b()
     >>> ss=s()
     >>> rr=r()
     >>> ssrr=sr()
     >>> 4.5
     4.5
     >>> str(ss)
     's'
     >>> 
     """
 
 def test_hist_pof():
     ip = get_ipython()
     ip.run_cell(u"1+2", store_history=True)
     #raise Exception(ip.history_manager.session_number)
     #raise Exception(list(ip.history_manager._get_range_session()))
     with TemporaryDirectory() as td:
         tf = os.path.join(td, 'hist.py')
         ip.run_line_magic('history', '-pof %s' % tf)
         assert os.path.isfile(tf)
 
 
 def test_macro():
     ip = get_ipython()
     ip.history_manager.reset()   # Clear any existing history.
     cmds = ["a=1", "def b():\n  return a**2", "print(a,b())"]
     for i, cmd in enumerate(cmds, start=1):
         ip.history_manager.store_inputs(i, cmd)
     ip.magic("macro test 1-3")
     nt.assert_equal(ip.user_ns["test"].value, "\n".join(cmds)+"\n")
     
     # List macros
     nt.assert_in("test", ip.magic("macro"))
 
 
 def test_macro_run():
     """Test that we can run a multi-line macro successfully."""
     ip = get_ipython()
     ip.history_manager.reset()
     cmds = ["a=10", "a+=1", "print(a)", "%macro test 2-3"]
     for cmd in cmds:
         ip.run_cell(cmd, store_history=True)
     nt.assert_equal(ip.user_ns["test"].value, "a+=1\nprint(a)\n")
     with tt.AssertPrints("12"):
         ip.run_cell("test")
     with tt.AssertPrints("13"):
         ip.run_cell("test")
 
 
 def test_magic_magic():
     """Test %magic"""
     ip = get_ipython()
     with capture_output() as captured:
         ip.magic("magic")
     
     stdout = captured.stdout
     nt.assert_in('%magic', stdout)
     nt.assert_in('IPython', stdout)
     nt.assert_in('Available', stdout)
 
 
 @dec.skipif_not_numpy
 def test_numpy_reset_array_undec():
     "Test '%reset array' functionality"
     _ip.ex('import numpy as np')
     _ip.ex('a = np.empty(2)')
     nt.assert_in('a', _ip.user_ns)
     _ip.magic('reset -f array')
     nt.assert_not_in('a', _ip.user_ns)
 
 def test_reset_out():
     "Test '%reset out' magic"
     _ip.run_cell("parrot = 'dead'", store_history=True)
     # test '%reset -f out', make an Out prompt
     _ip.run_cell("parrot", store_history=True)
     nt.assert_true('dead' in [_ip.user_ns[x] for x in ('_','__','___')])
     _ip.magic('reset -f out')
     nt.assert_false('dead' in [_ip.user_ns[x] for x in ('_','__','___')])
     nt.assert_equal(len(_ip.user_ns['Out']), 0)
 
 def test_reset_in():
     "Test '%reset in' magic"
     # test '%reset -f in'
     _ip.run_cell("parrot", store_history=True)
     nt.assert_true('parrot' in [_ip.user_ns[x] for x in ('_i','_ii','_iii')])
     _ip.magic('%reset -f in')
     nt.assert_false('parrot' in [_ip.user_ns[x] for x in ('_i','_ii','_iii')])
     nt.assert_equal(len(set(_ip.user_ns['In'])), 1)
 
 def test_reset_dhist():
     "Test '%reset dhist' magic"
     _ip.run_cell("tmp = [d for d in _dh]") # copy before clearing
     _ip.magic('cd ' + os.path.dirname(nt.__file__))
     _ip.magic('cd -')
     nt.assert_true(len(_ip.user_ns['_dh']) > 0)
     _ip.magic('reset -f dhist')
     nt.assert_equal(len(_ip.user_ns['_dh']), 0)
     _ip.run_cell("_dh = [d for d in tmp]") #restore
 
 def test_reset_in_length():
     "Test that '%reset in' preserves In[] length"
     _ip.run_cell("print 'foo'")
     _ip.run_cell("reset -f in")
     nt.assert_equal(len(_ip.user_ns['In']), _ip.displayhook.prompt_count+1)
 
 class TestResetErrors(TestCase):
 
     def test_reset_redefine(self):
 
         @magics_class
         class KernelMagics(Magics):
               @line_magic
               def less(self, shell): pass
 
         _ip.register_magics(KernelMagics)
 
         with self.assertLogs() as cm:
             # hack, we want to just capture logs, but assertLogs fails if not
             # logs get produce.
             # so log one things we ignore.
             import logging as log_mod
             log = log_mod.getLogger()
             log.info('Nothing')
             # end hack.
             _ip.run_cell("reset -f")
 
         assert len(cm.output) == 1
         for out in cm.output:
             assert "Invalid alias" not in out
 
 def test_tb_syntaxerror():
     """test %tb after a SyntaxError"""
     ip = get_ipython()
     ip.run_cell("for")
     
     # trap and validate stdout
     save_stdout = sys.stdout
     try:
         sys.stdout = StringIO()
         ip.run_cell("%tb")
         out = sys.stdout.getvalue()
     finally:
         sys.stdout = save_stdout
     # trim output, and only check the last line
     last_line = out.rstrip().splitlines()[-1].strip()
     nt.assert_equal(last_line, "SyntaxError: invalid syntax")
 
 
 def test_time():
     ip = get_ipython()
     
     with tt.AssertPrints("Wall time: "):
         ip.run_cell("%time None")
     
     ip.run_cell("def f(kmjy):\n"
                 "    %time print (2*kmjy)")
     
     with tt.AssertPrints("Wall time: "):
         with tt.AssertPrints("hihi", suppress=False):
             ip.run_cell("f('hi')")
 
 def test_time_last_not_expression():
     ip.run_cell("%%time\n"
                 "var_1 = 1\n"
                 "var_2 = 2\n")
     assert ip.user_ns['var_1'] == 1
     del ip.user_ns['var_1']
     assert ip.user_ns['var_2'] == 2
     del ip.user_ns['var_2']
     
 
 @dec.skip_win32
 def test_time2():
     ip = get_ipython()
     
     with tt.AssertPrints("CPU times: user "):
         ip.run_cell("%time None")
 
 def test_time3():
     """Erroneous magic function calls, issue gh-3334"""
     ip = get_ipython()
     ip.user_ns.pop('run', None)
     
     with tt.AssertNotPrints("not found", channel='stderr'):
         ip.run_cell("%%time\n"
                     "run = 0\n"
                     "run += 1")
 
 def test_multiline_time():
     """Make sure last statement from time return a value."""
     ip = get_ipython()
     ip.user_ns.pop('run', None)
 
     ip.run_cell(dedent("""\
         %%time
         a = "ho"
         b = "hey"
         a+b
         """))
     nt.assert_equal(ip.user_ns_hidden['_'], 'hohey')
 
 def test_time_local_ns():
     """
     Test that local_ns is actually global_ns when running a cell magic
     """
     ip = get_ipython()
     ip.run_cell("%%time\n"
                 "myvar = 1")
     nt.assert_equal(ip.user_ns['myvar'], 1)
     del ip.user_ns['myvar']
 
 def test_doctest_mode():
     "Toggle doctest_mode twice, it should be a no-op and run without error"
     _ip.magic('doctest_mode')
     _ip.magic('doctest_mode')
 
 
 def test_parse_options():
     """Tests for basic options parsing in magics."""
     # These are only the most minimal of tests, more should be added later.  At
     # the very least we check that basic text/unicode calls work OK.
     m = DummyMagics(_ip)
     nt.assert_equal(m.parse_options('foo', '')[1], 'foo')
     nt.assert_equal(m.parse_options(u'foo', '')[1], u'foo')
 
 
 def test_parse_options_preserve_non_option_string():
     """Test to assert preservation of non-option part of magic-block, while parsing magic options."""
     m = DummyMagics(_ip)
     opts, stmt = m.parse_options(
         " -n1  -r 13 _ = 314 + foo", "n:r:", preserve_non_opts=True
     )
     nt.assert_equal(opts, {"n": "1", "r": "13"})
     nt.assert_equal(stmt, "_ = 314 + foo")
 
 
 def test_run_magic_preserve_code_block():
     """Test to assert preservation of non-option part of magic-block, while running magic."""
     _ip.user_ns["spaces"] = []
     _ip.magic("timeit -n1 -r1 spaces.append([s.count(' ') for s in ['document']])")
     assert _ip.user_ns["spaces"] == [[0]]
 
 
 def test_dirops():
     """Test various directory handling operations."""
     # curpath = lambda :os.path.splitdrive(os.getcwd())[1].replace('\\','/')
     curpath = os.getcwd
     startdir = os.getcwd()
     ipdir = os.path.realpath(_ip.ipython_dir)
     try:
         _ip.magic('cd "%s"' % ipdir)
         nt.assert_equal(curpath(), ipdir)
         _ip.magic('cd -')
         nt.assert_equal(curpath(), startdir)
         _ip.magic('pushd "%s"' % ipdir)
         nt.assert_equal(curpath(), ipdir)
         _ip.magic('popd')
         nt.assert_equal(curpath(), startdir)
     finally:
         os.chdir(startdir)
 
 
 def test_cd_force_quiet():
     """Test OSMagics.cd_force_quiet option"""
     _ip.config.OSMagics.cd_force_quiet = True
     osmagics = osm.OSMagics(shell=_ip)
 
     startdir = os.getcwd()
     ipdir = os.path.realpath(_ip.ipython_dir)
 
     try:
         with tt.AssertNotPrints(ipdir):
             osmagics.cd('"%s"' % ipdir)
         with tt.AssertNotPrints(startdir):
             osmagics.cd('-')
     finally:
         os.chdir(startdir)
 
 
 def test_xmode():
     # Calling xmode three times should be a no-op
     xmode = _ip.InteractiveTB.mode
     for i in range(4):
         _ip.magic("xmode")
     nt.assert_equal(_ip.InteractiveTB.mode, xmode)
     
 def test_reset_hard():
     monitor = []
     class A(object):
         def __del__(self):
             monitor.append(1)
         def __repr__(self):
             return "<A instance>"
             
     _ip.user_ns["a"] = A()
     _ip.run_cell("a")
     
     nt.assert_equal(monitor, [])
     _ip.magic("reset -f")
     nt.assert_equal(monitor, [1])
     
 class TestXdel(tt.TempFileMixin):
     def test_xdel(self):
         """Test that references from %run are cleared by xdel."""
         src = ("class A(object):\n"
                "    monitor = []\n"
                "    def __del__(self):\n"
                "        self.monitor.append(1)\n"
                "a = A()\n")
         self.mktmp(src)
         # %run creates some hidden references...
         _ip.magic("run %s" % self.fname)
         # ... as does the displayhook.
         _ip.run_cell("a")
         
         monitor = _ip.user_ns["A"].monitor
         nt.assert_equal(monitor, [])
         
         _ip.magic("xdel a")
         
         # Check that a's __del__ method has been called.
         nt.assert_equal(monitor, [1])
 
 def doctest_who():
     """doctest for %who
     
     In [1]: %reset -f
     
     In [2]: alpha = 123
     
     In [3]: beta = 'beta'
     
     In [4]: %who int
     alpha
     
     In [5]: %who str
     beta
     
     In [6]: %whos
     Variable   Type    Data/Info
     ----------------------------
     alpha      int     123
     beta       str     beta
     
     In [7]: %who_ls
     Out[7]: ['alpha', 'beta']
     """
 
 def test_whos():
     """Check that whos is protected against objects where repr() fails."""
     class A(object):
         def __repr__(self):
             raise Exception()
     _ip.user_ns['a'] = A()
     _ip.magic("whos")
 
 def doctest_precision():
     """doctest for %precision
     
     In [1]: f = get_ipython().display_formatter.formatters['text/plain']
     
     In [2]: %precision 5
     Out[2]: '%.5f'
     
     In [3]: f.float_format
     Out[3]: '%.5f'
     
     In [4]: %precision %e
     Out[4]: '%e'
     
     In [5]: f(3.1415927)
     Out[5]: '3.141593e+00'
     """
 
 def test_debug_magic():
     """Test debugging a small code with %debug
     
     In [1]: with PdbTestInput(['c']):
        ...:     %debug print("a b") #doctest: +ELLIPSIS
        ...:
     ...
     ipdb> c
     a b
     In [2]:
     """
 
 def test_psearch():
     with tt.AssertPrints("dict.fromkeys"):
         _ip.run_cell("dict.fr*?")
     with tt.AssertPrints("π.is_integer"):
         _ip.run_cell("π = 3.14;\nπ.is_integ*?")
 
 def test_timeit_shlex():
     """test shlex issues with timeit (#1109)"""
     _ip.ex("def f(*a,**kw): pass")
     _ip.magic('timeit -n1 "this is a bug".count(" ")')
     _ip.magic('timeit -r1 -n1 f(" ", 1)')
     _ip.magic('timeit -r1 -n1 f(" ", 1, " ", 2, " ")')
     _ip.magic('timeit -r1 -n1 ("a " + "b")')
     _ip.magic('timeit -r1 -n1 f("a " + "b")')
     _ip.magic('timeit -r1 -n1 f("a " + "b ")')
 
 
 def test_timeit_special_syntax():
     "Test %%timeit with IPython special syntax"
     @register_line_magic
     def lmagic(line):
         ip = get_ipython()
         ip.user_ns['lmagic_out'] = line
 
     # line mode test
     _ip.run_line_magic('timeit', '-n1 -r1 %lmagic my line')
     nt.assert_equal(_ip.user_ns['lmagic_out'], 'my line')
     # cell mode test
     _ip.run_cell_magic('timeit', '-n1 -r1', '%lmagic my line2')
     nt.assert_equal(_ip.user_ns['lmagic_out'], 'my line2')
 
 def test_timeit_return():
     """
     test whether timeit -o return object
     """
 
     res = _ip.run_line_magic('timeit','-n10 -r10 -o 1')
     assert(res is not None)
 
 def test_timeit_quiet():
     """
     test quiet option of timeit magic
     """
     with tt.AssertNotPrints("loops"):
         _ip.run_cell("%timeit -n1 -r1 -q 1")
 
 def test_timeit_return_quiet():
     with tt.AssertNotPrints("loops"):
         res = _ip.run_line_magic('timeit', '-n1 -r1 -q -o 1')
     assert (res is not None)
 
 def test_timeit_invalid_return():
     with nt.assert_raises_regex(SyntaxError, "outside function"):
         _ip.run_line_magic('timeit', 'return')
 
 @dec.skipif(execution.profile is None)
 def test_prun_special_syntax():
     "Test %%prun with IPython special syntax"
     @register_line_magic
     def lmagic(line):
         ip = get_ipython()
         ip.user_ns['lmagic_out'] = line
 
     # line mode test
     _ip.run_line_magic('prun', '-q %lmagic my line')
     nt.assert_equal(_ip.user_ns['lmagic_out'], 'my line')
     # cell mode test
     _ip.run_cell_magic('prun', '-q', '%lmagic my line2')
     nt.assert_equal(_ip.user_ns['lmagic_out'], 'my line2')
 
 @dec.skipif(execution.profile is None)
 def test_prun_quotes():
     "Test that prun does not clobber string escapes (GH #1302)"
     _ip.magic(r"prun -q x = '\t'")
     nt.assert_equal(_ip.user_ns['x'], '\t')
 
 def test_extension():
     # Debugging information for failures of this test
     print('sys.path:')
     for p in sys.path:
         print(' ', p)
     print('CWD', os.getcwd())
 
     nt.assert_raises(ImportError, _ip.magic, "load_ext daft_extension")
     daft_path = os.path.join(os.path.dirname(__file__), "daft_extension")
     sys.path.insert(0, daft_path)
     try:
         _ip.user_ns.pop('arq', None)
         invalidate_caches()   # Clear import caches
         _ip.magic("load_ext daft_extension")
         nt.assert_equal(_ip.user_ns['arq'], 185)
         _ip.magic("unload_ext daft_extension")
         assert 'arq' not in _ip.user_ns
     finally:
         sys.path.remove(daft_path)
 
 
 def test_notebook_export_json():
     _ip = get_ipython()
     _ip.history_manager.reset()   # Clear any existing history.
     cmds = [u"a=1", u"def b():\n  return a**2", u"print('noël, été', b())"]
     for i, cmd in enumerate(cmds, start=1):
         _ip.history_manager.store_inputs(i, cmd)
     with TemporaryDirectory() as td:
         outfile = os.path.join(td, "nb.ipynb")
         _ip.magic("notebook -e %s" % outfile)
 
 
 class TestEnv(TestCase):
 
     def test_env(self):
         env = _ip.magic("env")
         self.assertTrue(isinstance(env, dict))
 
     def test_env_secret(self):
         env = _ip.magic("env")
         hidden = "<hidden>"
         with mock.patch.dict(
             os.environ,
             {
                 "API_KEY": "abc123",
                 "SECRET_THING": "ssshhh",
                 "JUPYTER_TOKEN": "",
                 "VAR": "abc"
             }
         ):
             env = _ip.magic("env")
         assert env["API_KEY"] == hidden
         assert env["SECRET_THING"] == hidden
         assert env["JUPYTER_TOKEN"] == hidden
         assert env["VAR"] == "abc"
 
     def test_env_get_set_simple(self):
         env = _ip.magic("env var val1")
         self.assertEqual(env, None)
         self.assertEqual(os.environ['var'], 'val1')
         self.assertEqual(_ip.magic("env var"), 'val1')
         env = _ip.magic("env var=val2")
         self.assertEqual(env, None)
         self.assertEqual(os.environ['var'], 'val2')
 
     def test_env_get_set_complex(self):
         env = _ip.magic("env var 'val1 '' 'val2")
         self.assertEqual(env, None)
         self.assertEqual(os.environ['var'], "'val1 '' 'val2")
         self.assertEqual(_ip.magic("env var"), "'val1 '' 'val2")
         env = _ip.magic('env var=val2 val3="val4')
         self.assertEqual(env, None)
         self.assertEqual(os.environ['var'], 'val2 val3="val4')
 
     def test_env_set_bad_input(self):
         self.assertRaises(UsageError, lambda: _ip.magic("set_env var"))
 
     def test_env_set_whitespace(self):
         self.assertRaises(UsageError, lambda: _ip.magic("env var A=B"))
 
 
 class CellMagicTestCase(TestCase):
 
     def check_ident(self, magic):
         # Manually called, we get the result
         out = _ip.run_cell_magic(magic, 'a', 'b')
         nt.assert_equal(out, ('a','b'))
         # Via run_cell, it goes into the user's namespace via displayhook
         _ip.run_cell('%%' + magic +' c\nd\n')
         nt.assert_equal(_ip.user_ns['_'], ('c','d\n'))
 
     def test_cell_magic_func_deco(self):
         "Cell magic using simple decorator"
         @register_cell_magic
         def cellm(line, cell):
             return line, cell
 
         self.check_ident('cellm')
 
     def test_cell_magic_reg(self):
         "Cell magic manually registered"
         def cellm(line, cell):
             return line, cell
 
         _ip.register_magic_function(cellm, 'cell', 'cellm2')
         self.check_ident('cellm2')
 
     def test_cell_magic_class(self):
         "Cell magics declared via a class"
         @magics_class
         class MyMagics(Magics):
 
             @cell_magic
             def cellm3(self, line, cell):
                 return line, cell
 
         _ip.register_magics(MyMagics)
         self.check_ident('cellm3')
 
     def test_cell_magic_class2(self):
         "Cell magics declared via a class, #2"
         @magics_class
         class MyMagics2(Magics):
 
             @cell_magic('cellm4')
             def cellm33(self, line, cell):
                 return line, cell
             
         _ip.register_magics(MyMagics2)
         self.check_ident('cellm4')
         # Check that nothing is registered as 'cellm33'
         c33 = _ip.find_cell_magic('cellm33')
         nt.assert_equal(c33, None)
 
 def test_file():
     """Basic %%writefile"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, 'file1')
         ip.run_cell_magic("writefile", fname, u'\n'.join([
             'line1',
             'line2',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line2', s)
 
 @dec.skip_win32
 def test_file_single_quote():
     """Basic %%writefile with embedded single quotes"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, '\'file1\'')
         ip.run_cell_magic("writefile", fname, u'\n'.join([
             'line1',
             'line2',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line2', s)
 
 @dec.skip_win32
 def test_file_double_quote():
     """Basic %%writefile with embedded double quotes"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, '"file1"')
         ip.run_cell_magic("writefile", fname, u'\n'.join([
             'line1',
             'line2',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line2', s)
 
 def test_file_var_expand():
     """%%writefile $filename"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, 'file1')
         ip.user_ns['filename'] = fname
         ip.run_cell_magic("writefile", '$filename', u'\n'.join([
             'line1',
             'line2',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line2', s)
 
 def test_file_unicode():
     """%%writefile with unicode cell"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, 'file1')
         ip.run_cell_magic("writefile", fname, u'\n'.join([
             u'liné1',
             u'liné2',
         ]))
         with io.open(fname, encoding='utf-8') as f:
             s = f.read()
         nt.assert_in(u'liné1\n', s)
         nt.assert_in(u'liné2', s)
 
 def test_file_amend():
     """%%writefile -a amends files"""
     ip = get_ipython()
     with TemporaryDirectory() as td:
         fname = os.path.join(td, 'file2')
         ip.run_cell_magic("writefile", fname, u'\n'.join([
             'line1',
             'line2',
         ]))
         ip.run_cell_magic("writefile", "-a %s" % fname, u'\n'.join([
             'line3',
             'line4',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line3\n', s)
 
 def test_file_spaces():
     """%%file with spaces in filename"""
     ip = get_ipython()
     with TemporaryWorkingDirectory() as td:
         fname = "file name"
         ip.run_cell_magic("file", '"%s"'%fname, u'\n'.join([
             'line1',
             'line2',
         ]))
         s = Path(fname).read_text()
         nt.assert_in('line1\n', s)
         nt.assert_in('line2', s)
     
 def test_script_config():
     ip = get_ipython()
     ip.config.ScriptMagics.script_magics = ['whoda']
     sm = script.ScriptMagics(shell=ip)
     nt.assert_in('whoda', sm.magics['cell'])
 
 @dec.skip_win32
 def test_script_out():
     ip = get_ipython()
     ip.run_cell_magic("script", "--out output sh", "echo 'hi'")
     nt.assert_equal(ip.user_ns['output'], 'hi\n')
 
 @dec.skip_win32
 def test_script_err():
     ip = get_ipython()
     ip.run_cell_magic("script", "--err error sh", "echo 'hello' >&2")
     nt.assert_equal(ip.user_ns['error'], 'hello\n')
 
 @dec.skip_win32
 def test_script_out_err():
     ip = get_ipython()
     ip.run_cell_magic("script", "--out output --err error sh", "echo 'hi'\necho 'hello' >&2")
     nt.assert_equal(ip.user_ns['output'], 'hi\n')
     nt.assert_equal(ip.user_ns['error'], 'hello\n')
 
 @dec.skip_win32
 async def test_script_bg_out():
     ip = get_ipython()
     ip.run_cell_magic("script", "--bg --out output sh", "echo 'hi'")
     nt.assert_equal((await ip.user_ns["output"].read()), b"hi\n")
     ip.user_ns['output'].close()
 
 @dec.skip_win32
 async def test_script_bg_err():
     ip = get_ipython()
     ip.run_cell_magic("script", "--bg --err error sh", "echo 'hello' >&2")
     nt.assert_equal((await ip.user_ns["error"].read()), b"hello\n")
     ip.user_ns["error"].close()
 
 
 @dec.skip_win32
 async def test_script_bg_out_err():
     ip = get_ipython()
     ip.run_cell_magic(
         "script", "--bg --out output --err error sh", "echo 'hi'\necho 'hello' >&2"
     )
     nt.assert_equal((await ip.user_ns["output"].read()), b"hi\n")
     nt.assert_equal((await ip.user_ns["error"].read()), b"hello\n")
     ip.user_ns["output"].close()
     ip.user_ns["error"].close()
 
 
 def test_script_defaults():
     ip = get_ipython()
     for cmd in ['sh', 'bash', 'perl', 'ruby']:
         try:
             find_cmd(cmd)
         except Exception:
             pass
         else:
             nt.assert_in(cmd, ip.magics_manager.magics['cell'])
 
 
 @magics_class
 class FooFoo(Magics):
     """class with both %foo and %%foo magics"""
     @line_magic('foo')
     def line_foo(self, line):
         "I am line foo"
         pass
 
     @cell_magic("foo")
     def cell_foo(self, line, cell):
         "I am cell foo, not line foo"
         pass
 
 def test_line_cell_info():
     """%%foo and %foo magics are distinguishable to inspect"""
     ip = get_ipython()
     ip.magics_manager.register(FooFoo)
     oinfo = ip.object_inspect('foo')
     nt.assert_true(oinfo['found'])
     nt.assert_true(oinfo['ismagic'])
     
     oinfo = ip.object_inspect('%%foo')
     nt.assert_true(oinfo['found'])
     nt.assert_true(oinfo['ismagic'])
     nt.assert_equal(oinfo['docstring'], FooFoo.cell_foo.__doc__)
 
     oinfo = ip.object_inspect('%foo')
     nt.assert_true(oinfo['found'])
     nt.assert_true(oinfo['ismagic'])
     nt.assert_equal(oinfo['docstring'], FooFoo.line_foo.__doc__)
 
 def test_multiple_magics():
     ip = get_ipython()
     foo1 = FooFoo(ip)
     foo2 = FooFoo(ip)
     mm = ip.magics_manager
     mm.register(foo1)
     nt.assert_true(mm.magics['line']['foo'].__self__ is foo1)
     mm.register(foo2)
     nt.assert_true(mm.magics['line']['foo'].__self__ is foo2)
 
 def test_alias_magic():
     """Test %alias_magic."""
     ip = get_ipython()
     mm = ip.magics_manager
 
     # Basic operation: both cell and line magics are created, if possible.
     ip.run_line_magic('alias_magic', 'timeit_alias timeit')
     nt.assert_in('timeit_alias', mm.magics['line'])
     nt.assert_in('timeit_alias', mm.magics['cell'])
 
     # --cell is specified, line magic not created.
     ip.run_line_magic('alias_magic', '--cell timeit_cell_alias timeit')
     nt.assert_not_in('timeit_cell_alias', mm.magics['line'])
     nt.assert_in('timeit_cell_alias', mm.magics['cell'])
 
     # Test that line alias is created successfully.
     ip.run_line_magic('alias_magic', '--line env_alias env')
     nt.assert_equal(ip.run_line_magic('env', ''),
                     ip.run_line_magic('env_alias', ''))
 
     # Test that line alias with parameters passed in is created successfully.
     ip.run_line_magic('alias_magic', '--line history_alias history --params ' + shlex.quote('3'))
     nt.assert_in('history_alias', mm.magics['line'])
 
 
 def test_save():
     """Test %save."""
     ip = get_ipython()
     ip.history_manager.reset()   # Clear any existing history.
     cmds = [u"a=1", u"def b():\n  return a**2", u"print(a, b())"]
     for i, cmd in enumerate(cmds, start=1):
         ip.history_manager.store_inputs(i, cmd)
     with TemporaryDirectory() as tmpdir:
         file = os.path.join(tmpdir, "testsave.py")
         ip.run_line_magic("save", "%s 1-10" % file)
         content = Path(file).read_text()
         nt.assert_equal(content.count(cmds[0]), 1)
         nt.assert_in("coding: utf-8", content)
         ip.run_line_magic("save", "-a %s 1-10" % file)
         content = Path(file).read_text()
         nt.assert_equal(content.count(cmds[0]), 2)
         nt.assert_in("coding: utf-8", content)
 
 
+def test_save_with_no_args():
+    ip = get_ipython()
+    ip.history_manager.reset()  # Clear any existing history.
+    cmds = [u"a=1", u"def b():\n    return a**2", u"print(a, b())", "%save"]
+    for i, cmd in enumerate(cmds, start=1):
+        ip.history_manager.store_inputs(i, cmd)
+
+    with TemporaryDirectory() as tmpdir:
+        path = os.path.join(tmpdir, "testsave.py")
+        ip.run_line_magic("save", path)
+        content = Path(path).read_text()
+        expected_content = dedent(
+            """\
+            # coding: utf-8
+            a=1
+            def b():
+                return a**2
+            print(a, b())
+            """
+        )
+        nt.assert_equal(content, expected_content)
+
+
 def test_store():
     """Test %store."""
     ip = get_ipython()
     ip.run_line_magic('load_ext', 'storemagic')
     
     # make sure the storage is empty
     ip.run_line_magic('store', '-z')
     ip.user_ns['var'] = 42
     ip.run_line_magic('store', 'var')
     ip.user_ns['var'] = 39
     ip.run_line_magic('store', '-r')
     nt.assert_equal(ip.user_ns['var'], 42)
 
     ip.run_line_magic('store', '-d var')
     ip.user_ns['var'] = 39
     ip.run_line_magic('store' , '-r')
     nt.assert_equal(ip.user_ns['var'], 39)
 
 
 def _run_edit_test(arg_s, exp_filename=None,
                         exp_lineno=-1,
                         exp_contents=None,
                         exp_is_temp=None):
     ip = get_ipython()
     M = code.CodeMagics(ip)
     last_call = ['','']
     opts,args = M.parse_options(arg_s,'prxn:')
     filename, lineno, is_temp = M._find_edit_target(ip, args, opts, last_call)
         
     if exp_filename is not None:
         nt.assert_equal(exp_filename, filename)
     if exp_contents is not None:
         with io.open(filename, 'r', encoding='utf-8') as f:
             contents = f.read()
         nt.assert_equal(exp_contents, contents)
     if exp_lineno != -1:
         nt.assert_equal(exp_lineno, lineno)
     if exp_is_temp is not None:
         nt.assert_equal(exp_is_temp, is_temp)
 
 
 def test_edit_interactive():
     """%edit on interactively defined objects"""
     ip = get_ipython()
     n = ip.execution_count
     ip.run_cell(u"def foo(): return 1", store_history=True)
     
     try:
         _run_edit_test("foo")
     except code.InteractivelyDefined as e:
         nt.assert_equal(e.index, n)
     else:
         raise AssertionError("Should have raised InteractivelyDefined")
 
 
 def test_edit_cell():
     """%edit [cell id]"""
     ip = get_ipython()
     
     ip.run_cell(u"def foo(): return 1", store_history=True)
     
     # test
     _run_edit_test("1", exp_contents=ip.user_ns['In'][1], exp_is_temp=True)
 
 def test_edit_fname():
     """%edit file"""
     # test
     _run_edit_test("test file.py", exp_filename="test file.py")
 
 def test_bookmark():
     ip = get_ipython()
     ip.run_line_magic('bookmark', 'bmname')
     with tt.AssertPrints('bmname'):
         ip.run_line_magic('bookmark', '-l')
     ip.run_line_magic('bookmark', '-d bmname')
 
 def test_ls_magic():
     ip = get_ipython()
     json_formatter = ip.display_formatter.formatters['application/json']
     json_formatter.enabled = True
     lsmagic = ip.magic('lsmagic')
     with warnings.catch_warnings(record=True) as w:
         j = json_formatter(lsmagic)
     nt.assert_equal(sorted(j), ['cell', 'line'])
     nt.assert_equal(w, []) # no warnings
 
 def test_strip_initial_indent():
     def sii(s):
         lines = s.splitlines()
         return '\n'.join(code.strip_initial_indent(lines))
 
     nt.assert_equal(sii("  a = 1\nb = 2"), "a = 1\nb = 2")
     nt.assert_equal(sii("  a\n    b\nc"), "a\n  b\nc")
     nt.assert_equal(sii("a\n  b"), "a\n  b")
 
 def test_logging_magic_quiet_from_arg():
     _ip.config.LoggingMagics.quiet = False
     lm = logging.LoggingMagics(shell=_ip)
     with TemporaryDirectory() as td:
         try:
             with tt.AssertNotPrints(re.compile("Activating.*")):
                 lm.logstart('-q {}'.format(
                         os.path.join(td, "quiet_from_arg.log")))
         finally:
             _ip.logger.logstop()
 
 def test_logging_magic_quiet_from_config():
     _ip.config.LoggingMagics.quiet = True
     lm = logging.LoggingMagics(shell=_ip)
     with TemporaryDirectory() as td:
         try:
             with tt.AssertNotPrints(re.compile("Activating.*")):
                 lm.logstart(os.path.join(td, "quiet_from_config.log"))
         finally:
             _ip.logger.logstop()
 
 
 def test_logging_magic_not_quiet():
     _ip.config.LoggingMagics.quiet = False
     lm = logging.LoggingMagics(shell=_ip)
     with TemporaryDirectory() as td:
         try:
             with tt.AssertPrints(re.compile("Activating.*")):
                 lm.logstart(os.path.join(td, "not_quiet.log"))
         finally:
             _ip.logger.logstop()
 
 
 def test_time_no_var_expand():
     _ip.user_ns['a'] = 5
     _ip.user_ns['b'] = []
     _ip.magic('time b.append("{a}")')
     assert _ip.user_ns['b'] == ['{a}']
 
 
 # this is slow, put at the end for local testing.
 def test_timeit_arguments():
     "Test valid timeit arguments, should not cause SyntaxError (GH #1269)"
     if sys.version_info < (3,7):
         _ip.magic("timeit -n1 -r1 ('#')")
     else:
         # 3.7 optimize no-op statement like above out, and complain there is
         # nothing in the for loop.
         _ip.magic("timeit -n1 -r1 a=('#')")
 
 
 TEST_MODULE = """
 print('Loaded my_tmp')
 if __name__ == "__main__":
     print('I just ran a script')
 """
 
 
 def test_run_module_from_import_hook():
     "Test that a module can be loaded via an import hook"
     with TemporaryDirectory() as tmpdir:
         fullpath = os.path.join(tmpdir, 'my_tmp.py')
         Path(fullpath).write_text(TEST_MODULE)
 
         class MyTempImporter(object):
             def __init__(self):
                 pass
 
             def find_module(self, fullname, path=None):
                 if 'my_tmp' in fullname:
                     return self
                 return None
 
             def load_module(self, name):
                 import imp
                 return imp.load_source('my_tmp', fullpath)
 
             def get_code(self, fullname):
                 return compile(Path(fullpath).read_text(), "foo", "exec")
 
             def is_package(self, __):
                 return False
 
         sys.meta_path.insert(0, MyTempImporter())
 
         with capture_output() as captured:
             _ip.magic("run -m my_tmp")
             _ip.run_cell("import my_tmp")
 
         output = "Loaded my_tmp\nI just ran a script\nLoaded my_tmp\n"
         nt.assert_equal(output, captured.stdout)
 
         sys.meta_path.pop(0)