Small docstring/usage message cleanups.

IPython/core/history.py

@@ -1,800 +1,800 b''
 """ History related magics and functionality """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2010 The IPython Development Team.
 #
 #  Distributed under the terms of the BSD License.
 #
 #  The full license is in the file COPYING.txt, distributed with this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib imports
 import atexit
 import datetime
 import os
 import re
 import sqlite3
 import threading
 
 # Our own packages
 from IPython.config.configurable import Configurable
 
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import io
 from IPython.utils.traitlets import Bool, Dict, Instance, Int, List, Unicode
 from IPython.utils.warn import warn
 
 #-----------------------------------------------------------------------------
 # Classes and functions
 #-----------------------------------------------------------------------------
 
 class HistoryManager(Configurable):
     """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')
     # 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()
     def _dir_hist_default(self):
         try:
             return [os.getcwdu()]
         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()
 
     # String holding the path to the history file
     hist_file = Unicode(config=True)
 
     # The SQLite database
     db = Instance(sqlite3.Connection)
     # The number of the current session in the history database
     session_number = Int()
     # Should we log output to the database? (default no)
     db_log_output = Bool(False, config=True)
     # Write to database every x commands (higher values save disk access & power)
     #  Values of 1 or less effectively disable caching. 
     db_cache_size = Int(0, 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')
     # N.B. Event is a function returning an instance of _Event.
     save_flag = Instance(threading._Event)
     
     # 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, 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)
 
         if self.hist_file == u'':
             # No one has set the hist_file, yet.
             histfname = 'history'
             self.hist_file = os.path.join(shell.profile_dir.location, histfname + '.sqlite')
 
         try:
             self.init_db()
         except sqlite3.DatabaseError:
             if os.path.isfile(self.hist_file):
                 # Try to move the file out of the way.
                 newpath = os.path.join(self.shell.profile_dir.location, "hist-corrupt.sqlite")
                 os.rename(self.hist_file, newpath)
                 print("ERROR! History file wasn't a valid SQLite database.",
                 "It was moved to %s" % newpath, "and a new file created.")
                 self.init_db()
             else:
                 # The hist_file is probably :memory: or something else.
                 raise
                 
         self.save_flag = threading.Event()
         self.db_input_cache_lock = threading.Lock()
         self.db_output_cache_lock = threading.Lock()
         self.save_thread = HistorySavingThread(self)
         self.save_thread.start()
 
         self.new_session()
 
         
     def init_db(self):
         """Connect to the database, and create tables if necessary."""
         self.db = sqlite3.connect(self.hist_file)
         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()
     
     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[:] = [os.getcwdu()]
         
         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 _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
         
     
     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))
         
     def search(self, pattern="*", raw=True, search_raw=True,
                                                         output=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`
         
         Returns
         -------
         Tuples as :meth:`get_range`
         """
         tosearch = "source_raw" if search_raw else "source"
         if output:
             tosearch = "history." + tosearch
         self.writeout_cache()
         return self._run_sql("WHERE %s GLOB ?" % tosearch, (pattern,),
                                     raw=raw, output=output)
                                 
     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:
             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
         -------
         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 or session==self.session_number:   # Current session
             return self._get_range_session(start, stop, raw, output)
         if session < 0:
             session += self.session_number
             
         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.
         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
     
     ## ----------------------------
     ## 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 }
         self.shell.user_ns.update(to_main)
         
     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)
     
     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
     def __init__(self, history_manager):
         super(HistorySavingThread, self).__init__()
         self.history_manager = history_manager
         atexit.register(self.stop)
         
     def run(self):
         # We need a separate db connection per thread:
         try:
             self.db = sqlite3.connect(self.history_manager.hist_file)
             while True:
                 self.history_manager.save_flag.wait()
                 if self.stop_now:
                     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+)                    # Only the start line num is compulsory
 ((?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).
     
     Examples
     --------
     list(extract_input_ranges("~8/5-~7/4 2"))
     [(-8, 5, None), (-7, 1, 4), (0, 2, 3)]
     """
     for range_str in ranges_str.split():
         rmatch = range_re.match(range_str)
         if not rmatch:
             continue
         start = int(rmatch.group("start"))
         end = rmatch.group("end")
         end = int(end) if end else start+1   # If no end specified, get (a, a+1)
         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
 
         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)
 
 @skip_doctest
 def magic_history(self, parameter_s = ''):
     """Print input history (_i<n> variables), with most recent last.
     
     %history       -> print at most 40 inputs (some may be multi-line)\\
     %history n     -> print at most n inputs\\
     %history n1 n2 -> print inputs between n1 and n2 (n2 not included)\\
 
     By default, input history is printed without line numbers so it can be
     directly pasted into an editor. Use -n to show them.
 
     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
 
     Options:
 
       -n: print line numbers for each input.
       This feature is only available if numbered prompts are in use.
 
       -o: also print outputs for each input.
 
       -p: print classic '>>>' python prompts before each input.  This is useful
        for making documentation, and in conjunction with -o, for producing
        doctest-ready output.
 
       -r: (default) print the 'raw' history, i.e. the actual commands you typed.
       
       -t: 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().magic("%cd /")' instead of '%cd /'.
       
       -g: treat the arg as a pattern to grep for in (full) history.
       This includes the saved history (almost all commands ever written).
       Use '%hist -g' to show full saved history (may be very long).
       
       -l: get the last n lines from all sessions. Specify n as a single arg, or
       the default is the last 10 lines.
 
       -f FILENAME: instead of printing the output to the screen, redirect it to
        the given file.  The file is always overwritten, though IPython asks for
        confirmation first if it already exists.
        
     Examples
     --------
     ::
     
       In [6]: %hist -n 4 6
       4:a = 12
       5:print a**2
 
     """
 
     if not self.shell.displayhook.do_full_cache:
         print('This feature is only available if numbered prompts are in use.')
         return
     opts,args = self.parse_options(parameter_s,'noprtglf:',mode='string')
     
     # 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.
     try:
         outfname = opts['f']
     except KeyError:
         outfile = io.stdout  # default
         # We don't want to close stdout at the end!
         close_at_end = False
     else:
         if os.path.exists(outfname):
             if not io.ask_yes_no("File %r exists. Overwrite?" % outfname): 
                 print('Aborting.')
                 return
 
         outfile = open(outfname,'w')
         close_at_end = True
     
     print_nums = 'n' in opts
     get_output = 'o' in opts
     pyprompts = 'p' in opts
     # Raw history is the default
     raw = not('t' in opts)
             
     default_length = 40
     pattern = None
     
     if 'g' in opts:         # Glob search
         pattern = "*" + args + "*" if args else "*"
         hist = history_manager.search(pattern, raw=raw, output=get_output)
         print_nums = True
     elif 'l' in opts:       # Get 'tail'
         try:
             n = int(args)
         except ValueError, IndexError:
             n = 10
         hist = history_manager.get_tail(n, raw=raw, output=get_output)
     else:
         if args:            # Get history by ranges
             hist = history_manager.get_range_by_str(args, raw, get_output)
         else:               # Just get history for the current session
             hist = history_manager.get_range(raw=raw, output=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
         inline = inline.expandtabs(4).rstrip()
             
         multiline = "\n" in inline
         line_sep = '\n' if multiline else ' '
         if print_nums:
             print('%s:%s' % (_format_lineno(session, lineno).rjust(width),
                     line_sep),  file=outfile, end='')
         if pyprompts:
             print(">>> ", end="", 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()
 
 
 def magic_rep(self, arg):
-    r""" Repeat a command, or get command to input line for editing
+    r"""Repeat a command, or get command to input line for editing
 
     - %rep (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]: %rep
          In[4]: heivaan_ <== cursor blinking
     
     %rep 45
     
     Place history line 45 on the next input prompt. Use %hist to find
     out the number.
     
     %rep 1-4
     
     Combine the specified lines into one cell, and place it on the next
     input prompt. See %history for the slice syntax.
     
     %rep 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.set_next_input(str(self.shell.user_ns["_"]))
         return
                                 # Get history range
     histlines = self.history_manager.get_range_by_str(arg)
     cmd = "\n".join(x[2] for x in histlines)
     if cmd:
         self.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.history_manager.search("*"+arg+"*")
         for h in reversed([x[2] for x in histlines]):
             if 'rep' in h:
                 continue
             self.set_next_input(h.rstrip())
             return
     else:
         self.set_next_input(cmd.rstrip())
     print("Couldn't evaluate or find in history:", arg)
         
 def magic_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'])
         hist = self.history_manager.get_tail(n)
     elif "g" in opts:       # Search
         p = "*"+opts['g']+"*"
         hist = list(self.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.history_manager.get_range_by_str(args)
     else:                   # Last line
         hist = self.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.run_cell("\n".join(hist), store_history=False)
 
 
 def init_ipython(ip):
     ip.define_magic("rep", magic_rep) 
     ip.define_magic("recall", magic_rep)
     ip.define_magic("rerun", magic_rerun)
     ip.define_magic("hist",magic_history)    # Alternative name
     ip.define_magic("history",magic_history)
 
     # XXX - ipy_completers are in quarantine, need to be updated to new apis
     #import ipy_completers
     #ipy_completers.quick_completer('%hist' ,'-g -t -r -n')

IPython/core/usage.py

@@ -1,525 +1,524 b''
 # -*- coding: utf-8 -*-
 """Usage information for the main IPython applications.
 """
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2010  The IPython Development Team
 #  Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 import sys
 from IPython.core import release
 
 cl_usage = """\
 =========
  IPython
 =========
 
 Tools for Interactive Computing in Python
 =========================================
 
     A Python shell with automatic history (input and output), dynamic object
     introspection, easier configuration, command completion, access to the
     system shell and more.  IPython can also be embedded in running programs.
 
 
 Usage
------
 
     ipython [subcommand] [options] [files]
 
     If invoked with no options, it executes all the files listed in sequence
     and exits, use -i to enter interactive mode after running the files.  Files
     ending in .py will be treated as normal Python, but files ending in .ipy
     can contain special IPython syntax (magic commands, shell expansions, etc.)
 
     Almost all configuration in IPython is available via the command-line. Do
     `ipython --help-all` to see all available options.  For persistent
     configuration, look into your `ipython_config.py` configuration file for 
     details.
 
     This file is typically installed in the `IPYTHON_DIR` directory, and there
     is a separate configuration directory for each profile. The default profile
     directory will be located in $IPYTHON_DIR/profile_default. For Linux users,
     IPYTHON_DIR defaults to `$HOME/.config/ipython`, and for other Unix systems
     to `$HOME/.ipython`.  For Windows users, $HOME resolves to C:\\Documents
     and Settings\\YourUserName in most instances.
     
     To initialize a profile with the default configuration file, do::
     
       $> ipython profile create
     
     and start editing `IPYTHON_DIR/profile_default/ipython_config.py`
 
     In IPython's documentation, we will refer to this directory as
     `IPYTHON_DIR`, you can change its default location by creating an
     environment variable with this name and setting it to the desired path.
 
     For more information, see the manual available in HTML and PDF in your
     installation, or online at http://ipython.org/documentation.html.
 """
 
 interactive_usage = """
 IPython -- An enhanced Interactive Python
 =========================================
 
 IPython offers a combination of convenient shell features, special commands
 and a history mechanism for both input (command history) and output (results
 caching, similar to Mathematica). It is intended to be a fully compatible
 replacement for the standard Python interpreter, while offering vastly
 improved functionality and flexibility.
 
 At your system command line, type 'ipython -h' to see the command line
 options available. This document only describes interactive features.
 
 MAIN FEATURES
 
 * Access to the standard Python help. As of Python 2.1, a help system is
   available with access to object docstrings and the Python manuals. Simply
   type 'help' (no quotes) to access it.
 
 * Magic commands: type %magic for information on the magic subsystem.
 
 * System command aliases, via the %alias command or the ipythonrc config file.
 
 * Dynamic object information:
 
   Typing ?word or word? prints detailed information about an object.  If
   certain strings in the object are too long (docstrings, code, etc.) they get
   snipped in the center for brevity.
 
   Typing ??word or word?? gives access to the full information without
   snipping long strings. Long strings are sent to the screen through the less
   pager if longer than the screen, printed otherwise.
 
   The ?/?? system gives access to the full source code for any object (if
   available), shows function prototypes and other useful information.
 
   If you just want to see an object's docstring, type '%pdoc object' (without
   quotes, and without % if you have automagic on).
 
   Both %pdoc and ?/?? give you access to documentation even on things which are
   not explicitely defined. Try for example typing {}.get? or after import os,
   type os.path.abspath??. The magic functions %pdef, %source and %file operate
   similarly.
 
 * Completion in the local namespace, by typing TAB at the prompt.
 
   At any time, hitting tab will complete any available python commands or
   variable names, and show you a list of the possible completions if there's
   no unambiguous one. It will also complete filenames in the current directory.
 
   This feature requires the readline and rlcomplete modules, so it won't work
   if your Python lacks readline support (such as under Windows).
 
 * Search previous command history in two ways (also requires readline):
 
   - Start typing, and then use Ctrl-p (previous,up) and Ctrl-n (next,down) to
   search through only the history items that match what you've typed so
   far. If you use Ctrl-p/Ctrl-n at a blank prompt, they just behave like
   normal arrow keys.
 
   - Hit Ctrl-r: opens a search prompt. Begin typing and the system searches
   your history for lines that match what you've typed so far, completing as
   much as it can.
 
   - %hist: search history by index (this does *not* require readline).
 
 * Persistent command history across sessions.
 
 * Logging of input with the ability to save and restore a working session.
   
 * System escape with !. Typing !ls will run 'ls' in the current directory.
 
 * The reload command does a 'deep' reload of a module: changes made to the
   module since you imported will actually be available without having to exit.
 
 * Verbose and colored exception traceback printouts. See the magic xmode and
   xcolor functions for details (just type %magic).
 
 * Input caching system:
 
   IPython offers numbered prompts (In/Out) with input and output caching. All
   input is saved and can be retrieved as variables (besides the usual arrow
   key recall).
 
   The following GLOBAL variables always exist (so don't overwrite them!):
   _i: stores previous input.
   _ii: next previous.
   _iii: next-next previous.
   _ih : a list of all input _ih[n] is the input from line n.
 
   Additionally, global variables named _i<n> are dynamically created (<n>
   being the prompt counter), such that _i<n> == _ih[<n>]
 
   For example, what you typed at prompt 14 is available as _i14 and _ih[14].
 
   You can create macros which contain multiple input lines from this history,
   for later re-execution, with the %macro function.
 
   The history function %hist allows you to see any part of your input history
   by printing a range of the _i variables. Note that inputs which contain
   magic functions (%) appear in the history with a prepended comment. This is
   because they aren't really valid Python code, so you can't exec them.
 
 * Output caching system:
 
   For output that is returned from actions, a system similar to the input
   cache exists but using _ instead of _i. Only actions that produce a result
   (NOT assignments, for example) are cached. If you are familiar with
   Mathematica, IPython's _ variables behave exactly like Mathematica's %
   variables.
 
   The following GLOBAL variables always exist (so don't overwrite them!):
   _ (one underscore): previous output.
   __ (two underscores): next previous.
   ___ (three underscores): next-next previous.
 
   Global variables named _<n> are dynamically created (<n> being the prompt
   counter), such that the result of output <n> is always available as _<n>.
 
   Finally, a global dictionary named _oh exists with entries for all lines
   which generated output.
 
 * Directory history:
 
   Your history of visited directories is kept in the global list _dh, and the
   magic %cd command can be used to go to any entry in that list.
 
 * Auto-parentheses and auto-quotes (adapted from Nathan Gray's LazyPython)
 
     1. Auto-parentheses
         Callable objects (i.e. functions, methods, etc) can be invoked like
         this (notice the commas between the arguments):
             >>> callable_ob arg1, arg2, arg3
         and the input will be translated to this:
             --> callable_ob(arg1, arg2, arg3)
         You can force auto-parentheses by using '/' as the first character
         of a line.  For example:
             >>> /globals             # becomes 'globals()'
         Note that the '/' MUST be the first character on the line!  This
         won't work:
             >>> print /globals    # syntax error
             
         In most cases the automatic algorithm should work, so you should
         rarely need to explicitly invoke /. One notable exception is if you
         are trying to call a function with a list of tuples as arguments (the
         parenthesis will confuse IPython):
             In [1]: zip (1,2,3),(4,5,6)  # won't work
         but this will work:
             In [2]: /zip (1,2,3),(4,5,6)
             ------> zip ((1,2,3),(4,5,6))
             Out[2]= [(1, 4), (2, 5), (3, 6)]        
 
         IPython tells you that it has altered your command line by
         displaying the new command line preceded by -->.  e.g.:
             In [18]: callable list
             -------> callable (list) 
 
     2. Auto-Quoting
         You can force auto-quoting of a function's arguments by using ',' as
         the first character of a line.  For example:
             >>> ,my_function /home/me   # becomes my_function("/home/me")
 
         If you use ';' instead, the whole argument is quoted as a single
         string (while ',' splits on whitespace):
             >>> ,my_function a b c   # becomes my_function("a","b","c")
             >>> ;my_function a b c   # becomes my_function("a b c")
 
         Note that the ',' MUST be the first character on the line!  This
         won't work:
             >>> x = ,my_function /home/me    # syntax error
 """
 
 interactive_usage_min =  """\
 An enhanced console for Python.
 Some of its features are:
 - Readline support if the readline library is present.
 - Tab completion in the local namespace.
 - Logging of input, see command-line options.
 - System shell escape via ! , eg !ls.
 - Magic commands, starting with a % (like %ls, %pwd, %cd, etc.)
 - Keeps track of locally defined variables via %who, %whos.
 - Show object information with a ? eg ?x or x? (use ?? for more info).
 """
 
 quick_reference = r"""
 IPython -- An enhanced Interactive Python - Quick Reference Card
 ================================================================
 
 obj?, obj??      : Get help, or more help for object (also works as
                    ?obj, ??obj).
 ?foo.*abc*       : List names in 'foo' containing 'abc' in them.
 %magic           : Information about IPython's 'magic' % functions.
 
 Magic functions are prefixed by %, and typically take their arguments without
 parentheses, quotes or even commas for convenience.
  
 Example magic function calls:
 
 %alias d ls -F   : 'd' is now an alias for 'ls -F'
 alias d ls -F    : Works if 'alias' not a python name
 alist = %alias   : Get list of aliases to 'alist'
 cd /usr/share    : Obvious. cd -<tab> to choose from visited dirs.
 %cd??            : See help AND source for magic %cd
 
 System commands:
     
 !cp a.txt b/     : System command escape, calls os.system()
 cp a.txt b/      : after %rehashx, most system commands work without !
 cp ${f}.txt $bar : Variable expansion in magics and system commands
 files = !ls /usr : Capture sytem command output
 files.s, files.l, files.n: "a b c", ['a','b','c'], 'a\nb\nc'
 
 History:
 
 _i, _ii, _iii    : Previous, next previous, next next previous input
 _i4, _ih[2:5]    : Input history line 4, lines 2-4
 exec _i81        : Execute input history line #81 again
 %rep 81          : Edit input history line #81        
 _, __, ___       : previous, next previous, next next previous output
 _dh              : Directory history
 _oh              : Output history
 %hist            : Command history. '%hist -g foo' search history for 'foo'
 
 Autocall:
 
 f 1,2            : f(1,2)
 /f 1,2           : f(1,2) (forced autoparen)
 ,f 1 2           : f("1","2")
 ;f 1 2           : f("1 2")
 
 Remember: TAB completion works in many contexts, not just file names
 or python names.
 
 The following magic functions are currently available:
 
 """
 
 gui_reference = """\
 ===============================
  The graphical IPython console
 ===============================
 
 This console is designed to emulate the look, feel and workflow of a terminal
 environment, while adding a number of enhancements that are simply not possible
 in a real terminal, such as inline syntax highlighting, true multiline editing,
 inline graphics and much more.
 
 This quick reference document contains the basic information you'll need to
 know to make the most efficient use of it.  For the various command line
 options available at startup, type ``ipython qtconsole --help`` at the command line.
 
 
 Multiline editing
 =================
 
 The graphical console is capable of true multiline editing, but it also tries
 to behave intuitively like a terminal when possible.  If you are used to
 IPyhton's old terminal behavior, you should find the transition painless, and
 once you learn a few basic keybindings it will be a much more efficient
 environment.
 
 For single expressions or indented blocks, the console behaves almost like the
 terminal IPython: single expressions are immediately evaluated, and indented
 blocks are evaluated once a single blank line is entered::
 
     In [1]: print "Hello IPython!"  # Enter was pressed at the end of the line
     Hello IPython!
     
     In [2]: for i in range(10):
        ...: 	print i,
        ...: 	
     0 1 2 3 4 5 6 7 8 9
 
 If you want to enter more than one expression in a single input block
 (something not possible in the terminal), you can use ``Control-Enter`` at the
 end of your first line instead of ``Enter``.  At that point the console goes
 into 'cell mode' and even if your inputs are not indented, it will continue
 accepting arbitrarily many lines until either you enter an extra blank line or
 you hit ``Shift-Enter`` (the key binding that forces execution).  When a
 multiline cell is entered, IPython analyzes it and executes its code producing
 an ``Out[n]`` prompt only for the last expression in it, while the rest of the
 cell is executed as if it was a script.  An example should clarify this::
 
     In [3]: x=1  # Hit C-Enter here
        ...: y=2  # from now on, regular Enter is sufficient
        ...: z=3
        ...: x**2  # This does *not* produce an Out[] value
        ...: x+y+z  # Only the last expression does
        ...: 
     Out[3]: 6
 
 The behavior where an extra blank line forces execution is only active if you
 are actually typing at the keyboard each line, and is meant to make it mimic
 the IPython terminal behavior.  If you paste a long chunk of input (for example
 a long script copied form an editor or web browser), it can contain arbitrarily
 many intermediate blank lines and they won't cause any problems.  As always,
 you can then make it execute by appending a blank line *at the end* or hitting
 ``Shift-Enter`` anywhere within the cell.
 
 With the up arrow key, you can retrieve previous blocks of input that contain
 multiple lines.  You can move inside of a multiline cell like you would in any
 text editor.  When you want it executed, the simplest thing to do is to hit the
 force execution key, ``Shift-Enter`` (though you can also navigate to the end
 and append a blank line by using ``Enter`` twice).
 
 If you've edited a multiline cell and accidentally navigate out of it with the
 up or down arrow keys, IPython will clear the cell and replace it with the
 contents of the one above or below that you navigated to.  If this was an
 accident and you want to retrieve the cell you were editing, use the Undo
 keybinding, ``Control-z``.
 
 
 Key bindings
 ============
 
 The IPython console supports most of the basic Emacs line-oriented keybindings,
 in addition to some of its own.
 
 The keybinding prefixes mean:
 
 - ``C``: Control
 - ``S``: Shift
 - ``M``: Meta (typically the Alt key)
 
 The keybindings themselves are:
 
 - ``Enter``: insert new line (may cause execution, see above).
 - ``C-Enter``: force new line, *never* causes execution.
 - ``S-Enter``: *force* execution regardless of where cursor is, no newline added.
 - ``C-c``: copy highlighted text to clipboard (prompts are automatically stripped).
 - ``C-S-c``: copy highlighted text to clipboard (prompts are not stripped).
 - ``C-v``: paste text from clipboard.
 - ``C-z``: undo (retrieves lost text if you move out of a cell with the arrows).
 - ``C-S-z``: redo.
 - ``C-o``: move to 'other' area, between pager and terminal.
 - ``C-l``: clear terminal.
 - ``C-a``: go to beginning of line.
 - ``C-e``: go to end of line.
 - ``C-k``: kill from cursor to the end of the line.
 - ``C-y``: yank (paste)
 - ``C-p``: previous line (like up arrow)
 - ``C-n``: next line (like down arrow)
 - ``C-f``: forward (like right arrow)
 - ``C-b``: back (like left arrow)
 - ``C-d``: delete next character.
 - ``M-<``: move to the beginning of the input region.
 - ``M->``: move to the end of the input region.
 - ``M-d``: delete next word.
 - ``M-Backspace``: delete previous word.
 - ``C-.``: force a kernel restart (a confirmation dialog appears).
 - ``C-+``: increase font size.
 - ``C--``: decrease font size.
 
 The IPython pager
 =================
 
 IPython will show long blocks of text from many sources using a builtin pager.
 You can control where this pager appears with the ``--paging`` command-line
 flag:
 
 - ``inside`` [default]: the pager is overlaid on top of the main terminal. You
   must quit the pager to get back to the terminal (similar to how a pager such
   as ``less`` or ``more`` works).
 
 - ``vsplit``: the console is made double-tall, and the pager appears on the
   bottom area when needed.  You can view its contents while using the terminal.
 
 - ``hsplit``: the console is made double-wide, and the pager appears on the
   right area when needed.  You can view its contents while using the terminal.
 
 - ``none``: the console never pages output.
 
 If you use the vertical or horizontal paging modes, you can navigate between
 terminal and pager as follows:
 
 - Tab key: goes from pager to terminal (but not the other way around).
 - Control-o: goes from one to another always.
 - Mouse: click on either.
 
 In all cases, the ``q`` or ``Escape`` keys quit the pager (when used with the
 focus on the pager area).
 
 Running subprocesses
 ====================
 
 The graphical IPython console uses the ``pexpect`` module to run subprocesses
 when you type ``!command``.  This has a number of advantages (true asynchronous
 output from subprocesses as well as very robust termination of rogue
 subprocesses with ``Control-C``), as well as some limitations.  The main
 limitation is that you can *not* interact back with the subprocess, so anything
 that invokes a pager or expects you to type input into it will block and hang
 (you can kill it with ``Control-C``).
 
 We have provided as magics ``%less`` to page files (aliased to ``%more``),
 ``%clear`` to clear the terminal, and ``%man`` on Linux/OSX.  These cover the
 most common commands you'd want to call in your subshell and that would cause
 problems if invoked via ``!cmd``, but you need to be aware of this limitation.
 
 Display
 =======
 
 The IPython console can now display objects in a variety of formats, including
 HTML, PNG and SVG. This is accomplished using the display functions in
 ``IPython.core.display``::
 
     In [4]: from IPython.core.display import display, display_html
 
     In [5]: from IPython.core.display import display_png, display_svg
 
 Python objects can simply be passed to these functions and the appropriate
 representations will be displayed in the console as long as the objects know
 how to compute those representations. The easiest way of teaching objects how
 to format themselves in various representations is to define special methods
 such as: ``_repr_html_``, ``_repr_svg_`` and ``_repr_png_``. IPython's display formatters
 can also be given custom formatter functions for various types::
 
     In [6]: ip = get_ipython()
 
     In [7]: html_formatter = ip.display_formatter.formatters['text/html']
 
     In [8]: html_formatter.for_type(Foo, foo_to_html)
 
 For further details, see ``IPython.core.formatters``.
 
 Inline matplotlib graphics
 ==========================
 
 The IPython console is capable of displaying matplotlib figures inline, in SVG
 or PNG format.  If started with the ``pylab=inline``, then all figures are
 rendered inline automatically (PNG by default).  If started with ``--pylab``
 or ``pylab=<your backend>``, then a GUI backend will be used, but IPython's
 ``display()`` and ``getfigs()`` functions can be used to view plots inline::
 
     In [9]: display(*getfigs())    # display all figures inline
 
     In[10]: display(*getfigs(1,2)) # display figures 1 and 2 inline
 """
 
 
 quick_guide = """\
 ?         -> Introduction and overview of IPython's features.
 %quickref -> Quick reference.
 help      -> Python's own help system.
 object?   -> Details about 'object', use 'object??' for extra details.
 """
 
 gui_note = """\
 %guiref   -> A brief reference about the graphical user interface.
 """
 
 default_banner_parts = [
     'Python %s\n' % (sys.version.split('\n')[0],),
     'Type "copyright", "credits" or "license" for more information.\n\n',
     'IPython %s -- An enhanced Interactive Python.\n' % (release.version,),
     quick_guide
 ]
 
 default_gui_banner_parts = default_banner_parts + [gui_note]
 
 default_banner = ''.join(default_banner_parts)
 
 default_gui_banner = ''.join(default_gui_banner_parts)