Removed codepath for Python < 3.6 #11949

IPython/core/interactiveshell.py

@@ -1,3708 +1,3701 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 asyncio
 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 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
 from ast import AST
 
 # NoOpContext is deprecated, but ipykernel imports it from here.
 # See https://github.com/ipython/ipykernel/issues/157
 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)
-if sys.version_info > (3, 5):
     from .async_helpers import _curio_runner, _trio_runner, _should_be_async
-else :
-    _curio_runner = _trio_runner = None
-
-    def _should_be_async(cell:str)->bool:
-        return False
 
 
 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.
 
     Parameter
     ---------
 
     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.
 
     Return
     ------
 
     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)
     
     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)
 
     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
 
     #-------------------------------------------------------------------------
     # 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 = CachingCompiler()
 
         # 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.
         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)
         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 a 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
         
         p = os.path.normcase(sys.executable)
         p_venv = os.path.normcase(os.environ['VIRTUAL_ENV'])
 
         # executable path should end like /bin/python or \\scripts\\python.exe
         p_exe_up2 = os.path.dirname(os.path.dirname(p))
         if p_exe_up2 and os.path.exists(p_venv) and os.path.samefile(p_exe_up2, p_venv):
             # Our exe is inside the virtualenv, don't need to do anything.
             return
 
         # 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 os.path.islink(p):
             p = os.path.normcase(os.path.join(os.path.dirname(p), os.readlink(p)))
             paths.append(p)
         
         # In Cygwin paths like "c:\..." and '\cygdrive\c\...' are possible
         if p_venv.startswith('\\cygdrive'):
             p_venv = p_venv[11:]
         elif len(p_venv) >= 2 and p_venv[1] == ':':
             p_venv = p_venv[2:]
 
         if any(p_venv in p for p in paths):
             # Running properly in the virtualenv, don't need to do anything
             return
         
         warn("Attempting to work in a virtualenv. If you encounter problems, please "
              "install IPython inside the virtualenv.")
         if sys.platform == "win32":
             virtual_env = os.path.join(os.environ['VIRTUAL_ENV'], 'Lib', 'site-packages') 
         else:
             virtual_env = os.path.join(os.environ['VIRTUAL_ENV'], 'lib',
                        'python%d.%d' % sys.version_info[:2], 'site-packages')
         
         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):
         """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()
 
         # 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:
                 raise NameError("name '%s' is not defined" % varname)
             # 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:
                 raise TypeError('regex must be a string or compiled pattern')
             # 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.
 
         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 excepts 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):
         """Actually show a traceback.
 
         Subclasses may override this method to put the traceback on a different
         place, like a side channel.
         """
         print(self.InteractiveTB.stb2text(stb))
 
     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.
 
         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.
 
         Simple usage example:
 
         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):
         """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."""
 
         newcomp = types.MethodType(completer,self.Completer)
         self.Completer.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,
         )
-        if sys.version_info >(3,5):
             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'] = sys._getframe(stack_depth).f_locals
             with self.builtin_trap:
                 result = fn(*args, **kwargs)
             return result
 
     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)
         # 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 = {
             u'status' : 'error',
             u'traceback' : stb,
             u'ename' : etype.__name__,
             u'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 = os.path.abspath(os.path.expanduser(fname))
 
         # Make sure we can open the file
         try:
             with open(fname):
                 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 = os.path.dirname(fname)
 
         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 = os.path.abspath(os.path.expanduser(fname))
 
         # Make sure we can open the file
         try:
             with open(fname):
                 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 = os.path.dirname(fname)
         
         def get_cells():
             """generator for sequence of code blocks to run"""
             if fname.endswith('.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:
                 with open(fname) as f:
                     yield f.read()
 
         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):
         """Internal method to run a complete IPython cell."""
         coro = self.run_cell_async(
             raw_cell,
             store_history=store_history,
             silent=silent,
             shell_futures=shell_futures,
         )
 
         # 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.should_run_async(raw_cell):
             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
         return
 
     def should_run_async(self, raw_cell: str) -> 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
         try:
             cell = self.transform_cell(raw_cell)
         except Exception:
             # any exception during transform will be raised
             # prior to execution
             return False
         return _should_be_async(cell)
 
     async def run_cell_async(self, raw_cell: str, store_history=False, silent=False, shell_futures=True) -> 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.
 
         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 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
 
         # 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 CachingCompiler()
 
         _run_async = False
 
         with self.builtin_trap:
             cell_name = self.compile.cache(cell, self.execution_count)
 
             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.
         """
         # 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
         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)
         pt.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."""
 
         dirname = tempfile.mkdtemp(prefix=prefix)
         self.tempdirs.append(dirname)
 
         handle, filename = tempfile.mkstemp('.py', prefix, dir=dirname)
         os.close(handle)  # On Windows, there can only be one open handle on a file
         self.tempfiles.append(filename)
 
         if data:
             with open(filename, 'w') as tmp_file:
                 tmp_file.write(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
             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.
 
         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)
 
     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.
 
         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:
             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)
 
         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 :
                     if not py_only :
                         with io_open(tgt,'r', encoding='latin1') as f :
                             return f.read()
                     raise ValueError(("'%s' seem to be unreadable.") % target)
             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:
             raise ValueError(("'%s' was not found in history, as a file, url, "
                                 "nor in the user namespace.") % target)
 
         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)
 
     #-------------------------------------------------------------------------
     # 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
         """
         # 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()
 
         # Cleanup all tempfiles and folders left around
         for tfile in self.tempfiles:
             try:
                 os.unlink(tfile)
             except OSError:
                 pass
 
         for tdir in self.tempdirs:
             try:
                 os.rmdir(tdir)
             except OSError:
                 pass
 
         # Clear all user namespaces to release all references cleanly.
         self.reset(new_session=False)
 
         # 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/lib/pretty.py

@@ -1,871 +1,871 b''
 # -*- coding: utf-8 -*-
 """
 Python advanced pretty printer.  This pretty printer is intended to
 replace the old `pprint` python module which does not allow developers
 to provide their own pretty print callbacks.
 
 This module is based on ruby's `prettyprint.rb` library by `Tanaka Akira`.
 
 
 Example Usage
 -------------
 
 To directly print the representation of an object use `pprint`::
 
     from pretty import pprint
     pprint(complex_object)
 
 To get a string of the output use `pretty`::
 
     from pretty import pretty
     string = pretty(complex_object)
 
 
 Extending
 ---------
 
 The pretty library allows developers to add pretty printing rules for their
 own objects.  This process is straightforward.  All you have to do is to
 add a `_repr_pretty_` method to your object and call the methods on the
 pretty printer passed::
 
     class MyObject(object):
 
         def _repr_pretty_(self, p, cycle):
             ...
 
 Here is an example implementation of a `_repr_pretty_` method for a list
 subclass::
 
     class MyList(list):
 
         def _repr_pretty_(self, p, cycle):
             if cycle:
                 p.text('MyList(...)')
             else:
                 with p.group(8, 'MyList([', '])'):
                     for idx, item in enumerate(self):
                         if idx:
                             p.text(',')
                             p.breakable()
                         p.pretty(item)
 
 The `cycle` parameter is `True` if pretty detected a cycle.  You *have* to
 react to that or the result is an infinite loop.  `p.text()` just adds
 non breaking text to the output, `p.breakable()` either adds a whitespace
 or breaks here.  If you pass it an argument it's used instead of the
 default space.  `p.pretty` prettyprints another object using the pretty print
 method.
 
 The first parameter to the `group` function specifies the extra indentation
 of the next line.  In this example the next item will either be on the same
 line (if the items are short enough) or aligned with the right edge of the
 opening bracket of `MyList`.
 
 If you just want to indent something you can use the group function
 without open / close parameters.  You can also use this code::
 
     with p.indent(2):
         ...
 
 Inheritance diagram:
 
 .. inheritance-diagram:: IPython.lib.pretty
    :parts: 3
 
 :copyright: 2007 by Armin Ronacher.
             Portions (c) 2009 by Robert Kern.
 :license: BSD License.
 """
 
 from contextlib import contextmanager
 import datetime
 import os
 import re
 import sys
 import types
 from collections import deque
 from inspect import signature
 from io import StringIO
 from warnings import warn
 
 from IPython.utils.decorators import undoc
 from IPython.utils.py3compat import PYPY
 
 __all__ = ['pretty', 'pprint', 'PrettyPrinter', 'RepresentationPrinter',
     'for_type', 'for_type_by_name']
 
 
 MAX_SEQ_LENGTH = 1000
 # The language spec says that dicts preserve order from 3.7, but CPython
 # does so from 3.6, so it seems likely that people will expect that.
-DICT_IS_ORDERED = sys.version_info >= (3, 6)
+DICT_IS_ORDERED = True
 _re_pattern_type = type(re.compile(''))
 
 def _safe_getattr(obj, attr, default=None):
     """Safe version of getattr.
 
     Same as getattr, but will return ``default`` on any Exception,
     rather than raising.
     """
     try:
         return getattr(obj, attr, default)
     except Exception:
         return default
 
 @undoc
 class CUnicodeIO(StringIO):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         warn(("CUnicodeIO is deprecated since IPython 6.0. "
               "Please use io.StringIO instead."),
              DeprecationWarning, stacklevel=2)
 
 def _sorted_for_pprint(items):
     """
     Sort the given items for pretty printing. Since some predictable
     sorting is better than no sorting at all, we sort on the string
     representation if normal sorting fails.
     """
     items = list(items)
     try:
         return sorted(items)
     except Exception:
         try:
             return sorted(items, key=str)
         except Exception:
             return items
 
 def pretty(obj, verbose=False, max_width=79, newline='\n', max_seq_length=MAX_SEQ_LENGTH):
     """
     Pretty print the object's representation.
     """
     stream = StringIO()
     printer = RepresentationPrinter(stream, verbose, max_width, newline, max_seq_length=max_seq_length)
     printer.pretty(obj)
     printer.flush()
     return stream.getvalue()
 
 
 def pprint(obj, verbose=False, max_width=79, newline='\n', max_seq_length=MAX_SEQ_LENGTH):
     """
     Like `pretty` but print to stdout.
     """
     printer = RepresentationPrinter(sys.stdout, verbose, max_width, newline, max_seq_length=max_seq_length)
     printer.pretty(obj)
     printer.flush()
     sys.stdout.write(newline)
     sys.stdout.flush()
 
 class _PrettyPrinterBase(object):
 
     @contextmanager
     def indent(self, indent):
         """with statement support for indenting/dedenting."""
         self.indentation += indent
         try:
             yield
         finally:
             self.indentation -= indent
 
     @contextmanager
     def group(self, indent=0, open='', close=''):
         """like begin_group / end_group but for the with statement."""
         self.begin_group(indent, open)
         try:
             yield
         finally:
             self.end_group(indent, close)
 
 class PrettyPrinter(_PrettyPrinterBase):
     """
     Baseclass for the `RepresentationPrinter` prettyprinter that is used to
     generate pretty reprs of objects.  Contrary to the `RepresentationPrinter`
     this printer knows nothing about the default pprinters or the `_repr_pretty_`
     callback method.
     """
 
     def __init__(self, output, max_width=79, newline='\n', max_seq_length=MAX_SEQ_LENGTH):
         self.output = output
         self.max_width = max_width
         self.newline = newline
         self.max_seq_length = max_seq_length
         self.output_width = 0
         self.buffer_width = 0
         self.buffer = deque()
 
         root_group = Group(0)
         self.group_stack = [root_group]
         self.group_queue = GroupQueue(root_group)
         self.indentation = 0
 
     def _break_outer_groups(self):
         while self.max_width < self.output_width + self.buffer_width:
             group = self.group_queue.deq()
             if not group:
                 return
             while group.breakables:
                 x = self.buffer.popleft()
                 self.output_width = x.output(self.output, self.output_width)
                 self.buffer_width -= x.width
             while self.buffer and isinstance(self.buffer[0], Text):
                 x = self.buffer.popleft()
                 self.output_width = x.output(self.output, self.output_width)
                 self.buffer_width -= x.width
 
     def text(self, obj):
         """Add literal text to the output."""
         width = len(obj)
         if self.buffer:
             text = self.buffer[-1]
             if not isinstance(text, Text):
                 text = Text()
                 self.buffer.append(text)
             text.add(obj, width)
             self.buffer_width += width
             self._break_outer_groups()
         else:
             self.output.write(obj)
             self.output_width += width
 
     def breakable(self, sep=' '):
         """
         Add a breakable separator to the output.  This does not mean that it
         will automatically break here.  If no breaking on this position takes
         place the `sep` is inserted which default to one space.
         """
         width = len(sep)
         group = self.group_stack[-1]
         if group.want_break:
             self.flush()
             self.output.write(self.newline)
             self.output.write(' ' * self.indentation)
             self.output_width = self.indentation
             self.buffer_width = 0
         else:
             self.buffer.append(Breakable(sep, width, self))
             self.buffer_width += width
             self._break_outer_groups()
 
     def break_(self):
         """
         Explicitly insert a newline into the output, maintaining correct indentation.
         """
         self.flush()
         self.output.write(self.newline)
         self.output.write(' ' * self.indentation)
         self.output_width = self.indentation
         self.buffer_width = 0
 
 
     def begin_group(self, indent=0, open=''):
         """
         Begin a group.  If you want support for python < 2.5 which doesn't has
         the with statement this is the preferred way:
 
             p.begin_group(1, '{')
             ...
             p.end_group(1, '}')
 
         The python 2.5 expression would be this:
 
             with p.group(1, '{', '}'):
                 ...
 
         The first parameter specifies the indentation for the next line (usually
         the width of the opening text), the second the opening text.  All
         parameters are optional.
         """
         if open:
             self.text(open)
         group = Group(self.group_stack[-1].depth + 1)
         self.group_stack.append(group)
         self.group_queue.enq(group)
         self.indentation += indent
 
     def _enumerate(self, seq):
         """like enumerate, but with an upper limit on the number of items"""
         for idx, x in enumerate(seq):
             if self.max_seq_length and idx >= self.max_seq_length:
                 self.text(',')
                 self.breakable()
                 self.text('...')
                 return
             yield idx, x
 
     def end_group(self, dedent=0, close=''):
         """End a group. See `begin_group` for more details."""
         self.indentation -= dedent
         group = self.group_stack.pop()
         if not group.breakables:
             self.group_queue.remove(group)
         if close:
             self.text(close)
 
     def flush(self):
         """Flush data that is left in the buffer."""
         for data in self.buffer:
             self.output_width += data.output(self.output, self.output_width)
         self.buffer.clear()
         self.buffer_width = 0
 
 
 def _get_mro(obj_class):
     """ Get a reasonable method resolution order of a class and its superclasses
     for both old-style and new-style classes.
     """
     if not hasattr(obj_class, '__mro__'):
         # Old-style class. Mix in object to make a fake new-style class.
         try:
             obj_class = type(obj_class.__name__, (obj_class, object), {})
         except TypeError:
             # Old-style extension type that does not descend from object.
             # FIXME: try to construct a more thorough MRO.
             mro = [obj_class]
         else:
             mro = obj_class.__mro__[1:-1]
     else:
         mro = obj_class.__mro__
     return mro
 
 
 class RepresentationPrinter(PrettyPrinter):
     """
     Special pretty printer that has a `pretty` method that calls the pretty
     printer for a python object.
 
     This class stores processing data on `self` so you must *never* use
     this class in a threaded environment.  Always lock it or reinstanciate
     it.
 
     Instances also have a verbose flag callbacks can access to control their
     output.  For example the default instance repr prints all attributes and
     methods that are not prefixed by an underscore if the printer is in
     verbose mode.
     """
 
     def __init__(self, output, verbose=False, max_width=79, newline='\n',
         singleton_pprinters=None, type_pprinters=None, deferred_pprinters=None,
         max_seq_length=MAX_SEQ_LENGTH):
 
         PrettyPrinter.__init__(self, output, max_width, newline, max_seq_length=max_seq_length)
         self.verbose = verbose
         self.stack = []
         if singleton_pprinters is None:
             singleton_pprinters = _singleton_pprinters.copy()
         self.singleton_pprinters = singleton_pprinters
         if type_pprinters is None:
             type_pprinters = _type_pprinters.copy()
         self.type_pprinters = type_pprinters
         if deferred_pprinters is None:
             deferred_pprinters = _deferred_type_pprinters.copy()
         self.deferred_pprinters = deferred_pprinters
 
     def pretty(self, obj):
         """Pretty print the given object."""
         obj_id = id(obj)
         cycle = obj_id in self.stack
         self.stack.append(obj_id)
         self.begin_group()
         try:
             obj_class = _safe_getattr(obj, '__class__', None) or type(obj)
             # First try to find registered singleton printers for the type.
             try:
                 printer = self.singleton_pprinters[obj_id]
             except (TypeError, KeyError):
                 pass
             else:
                 return printer(obj, self, cycle)
             # Next walk the mro and check for either:
             #   1) a registered printer
             #   2) a _repr_pretty_ method
             for cls in _get_mro(obj_class):
                 if cls in self.type_pprinters:
                     # printer registered in self.type_pprinters
                     return self.type_pprinters[cls](obj, self, cycle)
                 else:
                     # deferred printer
                     printer = self._in_deferred_types(cls)
                     if printer is not None:
                         return printer(obj, self, cycle)
                     else:
                         # Finally look for special method names.
                         # Some objects automatically create any requested
                         # attribute. Try to ignore most of them by checking for
                         # callability.
                         if '_repr_pretty_' in cls.__dict__:
                             meth = cls._repr_pretty_
                             if callable(meth):
                                 return meth(obj, self, cycle)
                         if cls is not object \
                                 and callable(cls.__dict__.get('__repr__')):
                             return _repr_pprint(obj, self, cycle)
 
             return _default_pprint(obj, self, cycle)
         finally:
             self.end_group()
             self.stack.pop()
 
     def _in_deferred_types(self, cls):
         """
         Check if the given class is specified in the deferred type registry.
 
         Returns the printer from the registry if it exists, and None if the
         class is not in the registry. Successful matches will be moved to the
         regular type registry for future use.
         """
         mod = _safe_getattr(cls, '__module__', None)
         name = _safe_getattr(cls, '__name__', None)
         key = (mod, name)
         printer = None
         if key in self.deferred_pprinters:
             # Move the printer over to the regular registry.
             printer = self.deferred_pprinters.pop(key)
             self.type_pprinters[cls] = printer
         return printer
 
 
 class Printable(object):
 
     def output(self, stream, output_width):
         return output_width
 
 
 class Text(Printable):
 
     def __init__(self):
         self.objs = []
         self.width = 0
 
     def output(self, stream, output_width):
         for obj in self.objs:
             stream.write(obj)
         return output_width + self.width
 
     def add(self, obj, width):
         self.objs.append(obj)
         self.width += width
 
 
 class Breakable(Printable):
 
     def __init__(self, seq, width, pretty):
         self.obj = seq
         self.width = width
         self.pretty = pretty
         self.indentation = pretty.indentation
         self.group = pretty.group_stack[-1]
         self.group.breakables.append(self)
 
     def output(self, stream, output_width):
         self.group.breakables.popleft()
         if self.group.want_break:
             stream.write(self.pretty.newline)
             stream.write(' ' * self.indentation)
             return self.indentation
         if not self.group.breakables:
             self.pretty.group_queue.remove(self.group)
         stream.write(self.obj)
         return output_width + self.width
 
 
 class Group(Printable):
 
     def __init__(self, depth):
         self.depth = depth
         self.breakables = deque()
         self.want_break = False
 
 
 class GroupQueue(object):
 
     def __init__(self, *groups):
         self.queue = []
         for group in groups:
             self.enq(group)
 
     def enq(self, group):
         depth = group.depth
         while depth > len(self.queue) - 1:
             self.queue.append([])
         self.queue[depth].append(group)
 
     def deq(self):
         for stack in self.queue:
             for idx, group in enumerate(reversed(stack)):
                 if group.breakables:
                     del stack[idx]
                     group.want_break = True
                     return group
             for group in stack:
                 group.want_break = True
             del stack[:]
 
     def remove(self, group):
         try:
             self.queue[group.depth].remove(group)
         except ValueError:
             pass
 
 
 def _default_pprint(obj, p, cycle):
     """
     The default print function.  Used if an object does not provide one and
     it's none of the builtin objects.
     """
     klass = _safe_getattr(obj, '__class__', None) or type(obj)
     if _safe_getattr(klass, '__repr__', None) is not object.__repr__:
         # A user-provided repr. Find newlines and replace them with p.break_()
         _repr_pprint(obj, p, cycle)
         return
     p.begin_group(1, '<')
     p.pretty(klass)
     p.text(' at 0x%x' % id(obj))
     if cycle:
         p.text(' ...')
     elif p.verbose:
         first = True
         for key in dir(obj):
             if not key.startswith('_'):
                 try:
                     value = getattr(obj, key)
                 except AttributeError:
                     continue
                 if isinstance(value, types.MethodType):
                     continue
                 if not first:
                     p.text(',')
                 p.breakable()
                 p.text(key)
                 p.text('=')
                 step = len(key) + 1
                 p.indentation += step
                 p.pretty(value)
                 p.indentation -= step
                 first = False
     p.end_group(1, '>')
 
 
 def _seq_pprinter_factory(start, end):
     """
     Factory that returns a pprint function useful for sequences.  Used by
     the default pprint for tuples, dicts, and lists.
     """
     def inner(obj, p, cycle):
         if cycle:
             return p.text(start + '...' + end)
         step = len(start)
         p.begin_group(step, start)
         for idx, x in p._enumerate(obj):
             if idx:
                 p.text(',')
                 p.breakable()
             p.pretty(x)
         if len(obj) == 1 and type(obj) is tuple:
             # Special case for 1-item tuples.
             p.text(',')
         p.end_group(step, end)
     return inner
 
 
 def _set_pprinter_factory(start, end):
     """
     Factory that returns a pprint function useful for sets and frozensets.
     """
     def inner(obj, p, cycle):
         if cycle:
             return p.text(start + '...' + end)
         if len(obj) == 0:
             # Special case.
             p.text(type(obj).__name__ + '()')
         else:
             step = len(start)
             p.begin_group(step, start)
             # Like dictionary keys, we will try to sort the items if there aren't too many
             if not (p.max_seq_length and len(obj) >= p.max_seq_length):
                 items = _sorted_for_pprint(obj)
             else:
                 items = obj
             for idx, x in p._enumerate(items):
                 if idx:
                     p.text(',')
                     p.breakable()
                 p.pretty(x)
             p.end_group(step, end)
     return inner
 
 
 def _dict_pprinter_factory(start, end):
     """
     Factory that returns a pprint function used by the default pprint of
     dicts and dict proxies.
     """
     def inner(obj, p, cycle):
         if cycle:
             return p.text('{...}')
         step = len(start)
         p.begin_group(step, start)
         keys = obj.keys()
         # if dict isn't large enough to be truncated, sort keys before displaying
         # From Python 3.7, dicts preserve order by definition, so we don't sort.
         if not DICT_IS_ORDERED \
                 and not (p.max_seq_length and len(obj) >= p.max_seq_length):
             keys = _sorted_for_pprint(keys)
         for idx, key in p._enumerate(keys):
             if idx:
                 p.text(',')
                 p.breakable()
             p.pretty(key)
             p.text(': ')
             p.pretty(obj[key])
         p.end_group(step, end)
     return inner
 
 
 def _super_pprint(obj, p, cycle):
     """The pprint for the super type."""
     p.begin_group(8, '<super: ')
     p.pretty(obj.__thisclass__)
     p.text(',')
     p.breakable()
     if PYPY: # In PyPy, super() objects don't have __self__ attributes
         dself = obj.__repr__.__self__
         p.pretty(None if dself is obj else dself)
     else:
         p.pretty(obj.__self__)
     p.end_group(8, '>')
 
 
 def _re_pattern_pprint(obj, p, cycle):
     """The pprint function for regular expression patterns."""
     p.text('re.compile(')
     pattern = repr(obj.pattern)
     if pattern[:1] in 'uU':
         pattern = pattern[1:]
         prefix = 'ur'
     else:
         prefix = 'r'
     pattern = prefix + pattern.replace('\\\\', '\\')
     p.text(pattern)
     if obj.flags:
         p.text(',')
         p.breakable()
         done_one = False
         for flag in ('TEMPLATE', 'IGNORECASE', 'LOCALE', 'MULTILINE', 'DOTALL',
             'UNICODE', 'VERBOSE', 'DEBUG'):
             if obj.flags & getattr(re, flag):
                 if done_one:
                     p.text('|')
                 p.text('re.' + flag)
                 done_one = True
     p.text(')')
 
 
 def _type_pprint(obj, p, cycle):
     """The pprint for classes and types."""
     # Heap allocated types might not have the module attribute,
     # and others may set it to None.
 
     # Checks for a __repr__ override in the metaclass. Can't compare the
     # type(obj).__repr__ directly because in PyPy the representation function
     # inherited from type isn't the same type.__repr__
     if [m for m in _get_mro(type(obj)) if "__repr__" in vars(m)][:1] != [type]:
         _repr_pprint(obj, p, cycle)
         return
 
     mod = _safe_getattr(obj, '__module__', None)
     try:
         name = obj.__qualname__
         if not isinstance(name, str):
             # This can happen if the type implements __qualname__ as a property
             # or other descriptor in Python 2.
             raise Exception("Try __name__")
     except Exception:
         name = obj.__name__
         if not isinstance(name, str):
             name = '<unknown type>'
 
     if mod in (None, '__builtin__', 'builtins', 'exceptions'):
         p.text(name)
     else:
         p.text(mod + '.' + name)
 
 
 def _repr_pprint(obj, p, cycle):
     """A pprint that just redirects to the normal repr function."""
     # Find newlines and replace them with p.break_()
     output = repr(obj)
     for idx,output_line in enumerate(output.splitlines()):
         if idx:
             p.break_()
         p.text(output_line)
 
 
 def _function_pprint(obj, p, cycle):
     """Base pprint for all functions and builtin functions."""
     name = _safe_getattr(obj, '__qualname__', obj.__name__)
     mod = obj.__module__
     if mod and mod not in ('__builtin__', 'builtins', 'exceptions'):
         name = mod + '.' + name
     try:
        func_def = name + str(signature(obj))
     except ValueError:
        func_def = name
     p.text('<function %s>' % func_def)
 
 
 def _exception_pprint(obj, p, cycle):
     """Base pprint for all exceptions."""
     name = getattr(obj.__class__, '__qualname__', obj.__class__.__name__)
     if obj.__class__.__module__ not in ('exceptions', 'builtins'):
         name = '%s.%s' % (obj.__class__.__module__, name)
     step = len(name) + 1
     p.begin_group(step, name + '(')
     for idx, arg in enumerate(getattr(obj, 'args', ())):
         if idx:
             p.text(',')
             p.breakable()
         p.pretty(arg)
     p.end_group(step, ')')
 
 
 #: the exception base
 try:
     _exception_base = BaseException
 except NameError:
     _exception_base = Exception
 
 
 #: printers for builtin types
 _type_pprinters = {
     int:                        _repr_pprint,
     float:                      _repr_pprint,
     str:                        _repr_pprint,
     tuple:                      _seq_pprinter_factory('(', ')'),
     list:                       _seq_pprinter_factory('[', ']'),
     dict:                       _dict_pprinter_factory('{', '}'),
     set:                        _set_pprinter_factory('{', '}'),
     frozenset:                  _set_pprinter_factory('frozenset({', '})'),
     super:                      _super_pprint,
     _re_pattern_type:           _re_pattern_pprint,
     type:                       _type_pprint,
     types.FunctionType:         _function_pprint,
     types.BuiltinFunctionType:  _function_pprint,
     types.MethodType:           _repr_pprint,
     datetime.datetime:          _repr_pprint,
     datetime.timedelta:         _repr_pprint,
     _exception_base:            _exception_pprint
 }
 
 # render os.environ like a dict
 _env_type = type(os.environ)
 # future-proof in case os.environ becomes a plain dict?
 if _env_type is not dict:
     _type_pprinters[_env_type] = _dict_pprinter_factory('environ{', '}')
 
 try:
     # In PyPy, types.DictProxyType is dict, setting the dictproxy printer
     # using dict.setdefault avoids overwriting the dict printer
     _type_pprinters.setdefault(types.DictProxyType,
                                _dict_pprinter_factory('dict_proxy({', '})'))
     _type_pprinters[types.ClassType] = _type_pprint
     _type_pprinters[types.SliceType] = _repr_pprint
 except AttributeError: # Python 3
     _type_pprinters[types.MappingProxyType] = \
         _dict_pprinter_factory('mappingproxy({', '})')
     _type_pprinters[slice] = _repr_pprint
 
 try:
     _type_pprinters[long] = _repr_pprint
     _type_pprinters[unicode] = _repr_pprint
 except NameError:
     _type_pprinters[range] = _repr_pprint
     _type_pprinters[bytes] = _repr_pprint
 
 #: printers for types specified by name
 _deferred_type_pprinters = {
 }
 
 def for_type(typ, func):
     """
     Add a pretty printer for a given type.
     """
     oldfunc = _type_pprinters.get(typ, None)
     if func is not None:
         # To support easy restoration of old pprinters, we need to ignore Nones.
         _type_pprinters[typ] = func
     return oldfunc
 
 def for_type_by_name(type_module, type_name, func):
     """
     Add a pretty printer for a type specified by the module and name of a type
     rather than the type object itself.
     """
     key = (type_module, type_name)
     oldfunc = _deferred_type_pprinters.get(key, None)
     if func is not None:
         # To support easy restoration of old pprinters, we need to ignore Nones.
         _deferred_type_pprinters[key] = func
     return oldfunc
 
 
 #: printers for the default singletons
 _singleton_pprinters = dict.fromkeys(map(id, [None, True, False, Ellipsis,
                                       NotImplemented]), _repr_pprint)
 
 
 def _defaultdict_pprint(obj, p, cycle):
     name = obj.__class__.__name__
     with p.group(len(name) + 1, name + '(', ')'):
         if cycle:
             p.text('...')
         else:
             p.pretty(obj.default_factory)
             p.text(',')
             p.breakable()
             p.pretty(dict(obj))
 
 def _ordereddict_pprint(obj, p, cycle):
     name = obj.__class__.__name__
     with p.group(len(name) + 1, name + '(', ')'):
         if cycle:
             p.text('...')
         elif len(obj):
             p.pretty(list(obj.items()))
 
 def _deque_pprint(obj, p, cycle):
     name = obj.__class__.__name__
     with p.group(len(name) + 1, name + '(', ')'):
         if cycle:
             p.text('...')
         else:
             p.pretty(list(obj))
 
 
 def _counter_pprint(obj, p, cycle):
     name = obj.__class__.__name__
     with p.group(len(name) + 1, name + '(', ')'):
         if cycle:
             p.text('...')
         elif len(obj):
             p.pretty(dict(obj))
 
 for_type_by_name('collections', 'defaultdict', _defaultdict_pprint)
 for_type_by_name('collections', 'OrderedDict', _ordereddict_pprint)
 for_type_by_name('collections', 'deque', _deque_pprint)
 for_type_by_name('collections', 'Counter', _counter_pprint)
 
 if __name__ == '__main__':
     from random import randrange
     class Foo(object):
         def __init__(self):
             self.foo = 1
             self.bar = re.compile(r'\s+')
             self.blub = dict.fromkeys(range(30), randrange(1, 40))
             self.hehe = 23424.234234
             self.list = ["blub", "blah", self]
 
         def get_foo(self):
             print("foo")
 
     pprint(Foo(), verbose=True)

IPython/terminal/interactiveshell.py

@@ -1,573 +1,562 b''
 """IPython terminal interface using prompt_toolkit"""
 
 import os
 import sys
 import warnings
 from warnings import warn
 
 from IPython.core.interactiveshell import InteractiveShell, InteractiveShellABC
 from IPython.utils import io
 from IPython.utils.py3compat import input
 from IPython.utils.terminal import toggle_set_term_title, set_term_title, restore_term_title
 from IPython.utils.process import abbrev_cwd
 from traitlets import (
     Bool, Unicode, Dict, Integer, observe, Instance, Type, default, Enum, Union,
     Any, validate
 )
 
 from prompt_toolkit.enums import DEFAULT_BUFFER, EditingMode
 from prompt_toolkit.filters import (HasFocus, Condition, IsDone)
 from prompt_toolkit.formatted_text import PygmentsTokens
 from prompt_toolkit.history import InMemoryHistory
 from prompt_toolkit.layout.processors import ConditionalProcessor, HighlightMatchingBracketProcessor
 from prompt_toolkit.output import ColorDepth
 from prompt_toolkit.patch_stdout import patch_stdout
 from prompt_toolkit.shortcuts import PromptSession, CompleteStyle, print_formatted_text
 from prompt_toolkit.styles import DynamicStyle, merge_styles
 from prompt_toolkit.styles.pygments import style_from_pygments_cls, style_from_pygments_dict
 
 from pygments.styles import get_style_by_name
 from pygments.style import Style
 from pygments.token import Token
 
 from .debugger import TerminalPdb, Pdb
 from .magics import TerminalMagics
 from .pt_inputhooks import get_inputhook_name_and_func
 from .prompts import Prompts, ClassicPrompts, RichPromptDisplayHook
 from .ptutils import IPythonPTCompleter, IPythonPTLexer
 from .shortcuts import create_ipython_shortcuts
 
 DISPLAY_BANNER_DEPRECATED = object()
 
 
 class _NoStyle(Style): pass
 
 
 
 _style_overrides_light_bg = {
             Token.Prompt: '#0000ff',
             Token.PromptNum: '#0000ee bold',
             Token.OutPrompt: '#cc0000',
             Token.OutPromptNum: '#bb0000 bold',
 }
 
 _style_overrides_linux = {
             Token.Prompt: '#00cc00',
             Token.PromptNum: '#00bb00 bold',
             Token.OutPrompt: '#cc0000',
             Token.OutPromptNum: '#bb0000 bold',
 }
 
 def get_default_editor():
     try:
         return os.environ['EDITOR']
     except KeyError:
         pass
     except UnicodeError:
         warn("$EDITOR environment variable is not pure ASCII. Using platform "
              "default editor.")
 
     if os.name == 'posix':
         return 'vi'  # the only one guaranteed to be there!
     else:
         return 'notepad' # same in Windows!
 
 # conservatively check for tty
 # overridden streams can result in things like:
 # - sys.stdin = None
 # - no isatty method
 for _name in ('stdin', 'stdout', 'stderr'):
     _stream = getattr(sys, _name)
     if not _stream or not hasattr(_stream, 'isatty') or not _stream.isatty():
         _is_tty = False
         break
 else:
     _is_tty = True
 
 
 _use_simple_prompt = ('IPY_TEST_SIMPLE_PROMPT' in os.environ) or (not _is_tty)
 
 class TerminalInteractiveShell(InteractiveShell):
     space_for_menu = Integer(6, help='Number of line at the bottom of the screen '
                                      'to reserve for the completion menu'
                             ).tag(config=True)
 
     pt_app = None
     debugger_history = None
 
     simple_prompt = Bool(_use_simple_prompt,
         help="""Use `raw_input` for the REPL, without completion and prompt colors.
 
             Useful when controlling IPython as a subprocess, and piping STDIN/OUT/ERR. Known usage are:
             IPython own testing machinery, and emacs inferior-shell integration through elpy.
 
             This mode default to `True` if the `IPY_TEST_SIMPLE_PROMPT`
             environment variable is set, or the current terminal is not a tty."""
             ).tag(config=True)
 
     @property
     def debugger_cls(self):
         return Pdb if self.simple_prompt else TerminalPdb
 
     confirm_exit = Bool(True,
         help="""
         Set to confirm when you try to exit IPython with an EOF (Control-D
         in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
         you can force a direct exit without any confirmation.""",
     ).tag(config=True)
 
     editing_mode = Unicode('emacs',
         help="Shortcut style to use at the prompt. 'vi' or 'emacs'.",
     ).tag(config=True)
 
     mouse_support = Bool(False,
         help="Enable mouse support in the prompt\n(Note: prevents selecting text with the mouse)"
     ).tag(config=True)
 
     # We don't load the list of styles for the help string, because loading
     # Pygments plugins takes time and can cause unexpected errors.
     highlighting_style = Union([Unicode('legacy'), Type(klass=Style)],
         help="""The name or class of a Pygments style to use for syntax
         highlighting. To see available styles, run `pygmentize -L styles`."""
     ).tag(config=True)
 
     @validate('editing_mode')
     def _validate_editing_mode(self, proposal):
         if proposal['value'].lower() == 'vim':
             proposal['value']= 'vi'
         elif proposal['value'].lower() == 'default':
             proposal['value']= 'emacs'
 
         if hasattr(EditingMode, proposal['value'].upper()):
             return proposal['value'].lower()
 
         return self.editing_mode
 
 
     @observe('editing_mode')
     def _editing_mode(self, change):
         u_mode = change.new.upper()
         if self.pt_app:
             self.pt_app.editing_mode = u_mode
 
     @observe('highlighting_style')
     @observe('colors')
     def _highlighting_style_changed(self, change):
         self.refresh_style()
 
     def refresh_style(self):
         self._style = self._make_style_from_name_or_cls(self.highlighting_style)
 
 
     highlighting_style_overrides = Dict(
         help="Override highlighting format for specific tokens"
     ).tag(config=True)
 
     true_color = Bool(False,
         help=("Use 24bit colors instead of 256 colors in prompt highlighting. "
               "If your terminal supports true color, the following command "
               "should print 'TRUECOLOR' in orange: "
               "printf \"\\x1b[38;2;255;100;0mTRUECOLOR\\x1b[0m\\n\"")
     ).tag(config=True)
 
     editor = Unicode(get_default_editor(),
         help="Set the editor used by IPython (default to $EDITOR/vi/notepad)."
     ).tag(config=True)
 
     prompts_class = Type(Prompts, help='Class used to generate Prompt token for prompt_toolkit').tag(config=True)
 
     prompts = Instance(Prompts)
 
     @default('prompts')
     def _prompts_default(self):
         return self.prompts_class(self)
 
 #    @observe('prompts')
 #    def _(self, change):
 #        self._update_layout()
 
     @default('displayhook_class')
     def _displayhook_class_default(self):
         return RichPromptDisplayHook
 
     term_title = Bool(True,
         help="Automatically set the terminal title"
     ).tag(config=True)
 
     term_title_format = Unicode("IPython: {cwd}",
         help="Customize the terminal title format.  This is a python format string. " +
              "Available substitutions are: {cwd}."
     ).tag(config=True)
 
     display_completions = Enum(('column', 'multicolumn','readlinelike'),
         help= ( "Options for displaying tab completions, 'column', 'multicolumn', and "
                 "'readlinelike'. These options are for `prompt_toolkit`, see "
                 "`prompt_toolkit` documentation for more information."
                 ),
         default_value='multicolumn').tag(config=True)
 
     highlight_matching_brackets = Bool(True,
         help="Highlight matching brackets.",
     ).tag(config=True)
 
     extra_open_editor_shortcuts = Bool(False,
         help="Enable vi (v) or Emacs (C-X C-E) shortcuts to open an external editor. "
              "This is in addition to the F2 binding, which is always enabled."
     ).tag(config=True)
 
     handle_return = Any(None,
         help="Provide an alternative handler to be called when the user presses "
              "Return. This is an advanced option intended for debugging, which "
              "may be changed or removed in later releases."
     ).tag(config=True)
 
     enable_history_search = Bool(True,
         help="Allows to enable/disable the prompt toolkit history search"
     ).tag(config=True)
 
     prompt_includes_vi_mode = Bool(True,
         help="Display the current vi mode (when using vi editing mode)."
     ).tag(config=True)
 
     @observe('term_title')
     def init_term_title(self, change=None):
         # Enable or disable the terminal title.
         if self.term_title:
             toggle_set_term_title(True)
             set_term_title(self.term_title_format.format(cwd=abbrev_cwd()))
         else:
             toggle_set_term_title(False)
 
     def restore_term_title(self):
         if self.term_title:
             restore_term_title()
 
     def init_display_formatter(self):
         super(TerminalInteractiveShell, self).init_display_formatter()
         # terminal only supports plain text
         self.display_formatter.active_types = ['text/plain']
         # disable `_ipython_display_`
         self.display_formatter.ipython_display_formatter.enabled = False
 
     def init_prompt_toolkit_cli(self):
         if self.simple_prompt:
             # Fall back to plain non-interactive output for tests.
             # This is very limited.
             def prompt():
                 prompt_text = "".join(x[1] for x in self.prompts.in_prompt_tokens())
                 lines = [input(prompt_text)]
                 prompt_continuation = "".join(x[1] for x in self.prompts.continuation_prompt_tokens())
                 while self.check_complete('\n'.join(lines))[0] == 'incomplete':
                     lines.append( input(prompt_continuation) )
                 return '\n'.join(lines)
             self.prompt_for_code = prompt
             return
 
         # Set up keyboard shortcuts
         key_bindings = create_ipython_shortcuts(self)
 
         # Pre-populate history from IPython's history database
         history = InMemoryHistory()
         last_cell = u""
         for __, ___, cell in self.history_manager.get_tail(self.history_load_length,
                                                         include_latest=True):
             # Ignore blank lines and consecutive duplicates
             cell = cell.rstrip()
             if cell and (cell != last_cell):
                 history.append_string(cell)
                 last_cell = cell
 
         self._style = self._make_style_from_name_or_cls(self.highlighting_style)
         self.style = DynamicStyle(lambda: self._style)
 
         editing_mode = getattr(EditingMode, self.editing_mode.upper())
 
         self.pt_app = PromptSession(
                             editing_mode=editing_mode,
                             key_bindings=key_bindings,
                             history=history,
                             completer=IPythonPTCompleter(shell=self),
                             enable_history_search = self.enable_history_search,
                             style=self.style,
                             include_default_pygments_style=False,
                             mouse_support=self.mouse_support,
                             enable_open_in_editor=self.extra_open_editor_shortcuts,
                             color_depth=self.color_depth,
                             **self._extra_prompt_options())
 
     def _make_style_from_name_or_cls(self, name_or_cls):
         """
         Small wrapper that make an IPython compatible style from a style name
 
         We need that to add style for prompt ... etc.
         """
         style_overrides = {}
         if name_or_cls == 'legacy':
             legacy = self.colors.lower()
             if legacy == 'linux':
                 style_cls = get_style_by_name('monokai')
                 style_overrides = _style_overrides_linux
             elif legacy == 'lightbg':
                 style_overrides = _style_overrides_light_bg
                 style_cls = get_style_by_name('pastie')
             elif legacy == 'neutral':
                 # The default theme needs to be visible on both a dark background
                 # and a light background, because we can't tell what the terminal
                 # looks like. These tweaks to the default theme help with that.
                 style_cls = get_style_by_name('default')
                 style_overrides.update({
                     Token.Number: '#007700',
                     Token.Operator: 'noinherit',
                     Token.String: '#BB6622',
                     Token.Name.Function: '#2080D0',
                     Token.Name.Class: 'bold #2080D0',
                     Token.Name.Namespace: 'bold #2080D0',
                     Token.Prompt: '#009900',
                     Token.PromptNum: '#ansibrightgreen bold',
                     Token.OutPrompt: '#990000',
                     Token.OutPromptNum: '#ansibrightred bold',
                 })
 
                 # Hack: Due to limited color support on the Windows console
                 # the prompt colors will be wrong without this
                 if os.name == 'nt':
                     style_overrides.update({
                         Token.Prompt: '#ansidarkgreen',
                         Token.PromptNum: '#ansigreen bold',
                         Token.OutPrompt: '#ansidarkred',
                         Token.OutPromptNum: '#ansired bold',
                     })
             elif legacy =='nocolor':
                 style_cls=_NoStyle
                 style_overrides = {}
             else :
                 raise ValueError('Got unknown colors: ', legacy)
         else :
             if isinstance(name_or_cls, str):
                 style_cls = get_style_by_name(name_or_cls)
             else:
                 style_cls = name_or_cls
             style_overrides = {
                 Token.Prompt: '#009900',
                 Token.PromptNum: '#ansibrightgreen bold',
                 Token.OutPrompt: '#990000',
                 Token.OutPromptNum: '#ansibrightred bold',
             }
         style_overrides.update(self.highlighting_style_overrides)
         style = merge_styles([
             style_from_pygments_cls(style_cls),
             style_from_pygments_dict(style_overrides),
         ])
 
         return style
 
     @property
     def pt_complete_style(self):
         return {
             'multicolumn': CompleteStyle.MULTI_COLUMN,
             'column': CompleteStyle.COLUMN,
             'readlinelike': CompleteStyle.READLINE_LIKE,
         }[self.display_completions]
 
     @property
     def color_depth(self):
         return (ColorDepth.TRUE_COLOR if self.true_color else None)
 
     def _extra_prompt_options(self):
         """
         Return the current layout option for the current Terminal InteractiveShell
         """
         def get_message():
             return PygmentsTokens(self.prompts.in_prompt_tokens())
 
         if self.editing_mode == 'emacs':
             # with emacs mode the prompt is (usually) static, so we call only
             # the function once. With VI mode it can toggle between [ins] and
             # [nor] so we can't precompute.
             # here I'm going to favor the default keybinding which almost
             # everybody uses to decrease CPU usage.
             # if we have issues with users with custom Prompts we can see how to
             # work around this.
             get_message = get_message()
 
         return {
                 'complete_in_thread': False,
                 'lexer':IPythonPTLexer(),
                 'reserve_space_for_menu':self.space_for_menu,
                 'message': get_message,
                 'prompt_continuation': (
                     lambda width, lineno, is_soft_wrap:
                         PygmentsTokens(self.prompts.continuation_prompt_tokens(width))),
                 'multiline': True,
                 'complete_style': self.pt_complete_style,
 
                 # Highlight matching brackets, but only when this setting is
                 # enabled, and only when the DEFAULT_BUFFER has the focus.
                 'input_processors': [ConditionalProcessor(
                         processor=HighlightMatchingBracketProcessor(chars='[](){}'),
                         filter=HasFocus(DEFAULT_BUFFER) & ~IsDone() &
                             Condition(lambda: self.highlight_matching_brackets))],
                 'inputhook': self.inputhook,
                 }
 
     def prompt_for_code(self):
         if self.rl_next_input:
             default = self.rl_next_input
             self.rl_next_input = None
         else:
             default = ''
 
         with patch_stdout(raw=True):
             text = self.pt_app.prompt(
                 default=default,
 #                pre_run=self.pre_prompt,# reset_current_buffer=True,
                 **self._extra_prompt_options())
         return text
 
-    def enable_win_unicode_console(self):
-        if sys.version_info >= (3, 6):
-            # Since PEP 528, Python uses the unicode APIs for the Windows
-            # console by default, so WUC shouldn't be needed.
-            return
-
-        import win_unicode_console
-        win_unicode_console.enable()
-
     def init_io(self):
         if sys.platform not in {'win32', 'cli'}:
             return
 
-        self.enable_win_unicode_console()
-
         import colorama
         colorama.init()
 
         # For some reason we make these wrappers around stdout/stderr.
         # For now, we need to reset them so all output gets coloured.
         # https://github.com/ipython/ipython/issues/8669
         # 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_magics(self):
         super(TerminalInteractiveShell, self).init_magics()
         self.register_magics(TerminalMagics)
 
     def init_alias(self):
         # The parent class defines aliases that can be safely used with any
         # frontend.
         super(TerminalInteractiveShell, self).init_alias()
 
         # 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'):
                 self.alias_manager.soft_define_alias(cmd, cmd)
 
 
     def __init__(self, *args, **kwargs):
         super(TerminalInteractiveShell, self).__init__(*args, **kwargs)
         self.init_prompt_toolkit_cli()
         self.init_term_title()
         self.keep_running = True
 
         self.debugger_history = InMemoryHistory()
 
     def ask_exit(self):
         self.keep_running = False
 
     rl_next_input = None
 
     def interact(self, display_banner=DISPLAY_BANNER_DEPRECATED):
 
         if display_banner is not DISPLAY_BANNER_DEPRECATED:
             warn('interact `display_banner` argument is deprecated since IPython 5.0. Call `show_banner()` if needed.', DeprecationWarning, stacklevel=2)
 
         self.keep_running = True
         while self.keep_running:
             print(self.separate_in, end='')
 
             try:
                 code = self.prompt_for_code()
             except EOFError:
                 if (not self.confirm_exit) \
                         or self.ask_yes_no('Do you really want to exit ([y]/n)?','y','n'):
                     self.ask_exit()
 
             else:
                 if code:
                     self.run_cell(code, store_history=True)
 
     def mainloop(self, display_banner=DISPLAY_BANNER_DEPRECATED):
         # An extra layer of protection in case someone mashing Ctrl-C breaks
         # out of our internal code.
         if display_banner is not DISPLAY_BANNER_DEPRECATED:
             warn('mainloop `display_banner` argument is deprecated since IPython 5.0. Call `show_banner()` if needed.', DeprecationWarning, stacklevel=2)
         while True:
             try:
                 self.interact()
                 break
             except KeyboardInterrupt as e:
                 print("\n%s escaped interact()\n" % type(e).__name__)
             finally:
                 # An interrupt during the eventloop will mess up the
                 # internal state of the prompt_toolkit library.
                 # Stopping the eventloop fixes this, see
                 # https://github.com/ipython/ipython/pull/9867
                 if hasattr(self, '_eventloop'):
                     self._eventloop.stop()
 
                 self.restore_term_title()
 
 
     _inputhook = None
     def inputhook(self, context):
         if self._inputhook is not None:
             self._inputhook(context)
 
     active_eventloop = None
     def enable_gui(self, gui=None):
         if gui:
             self.active_eventloop, self._inputhook =\
                 get_inputhook_name_and_func(gui)
         else:
             self.active_eventloop = self._inputhook = None
 
     # Run !system commands directly, not through pipes, so terminal programs
     # work correctly.
     system = InteractiveShell.system_raw
 
     def auto_rewrite_input(self, cmd):
         """Overridden from the parent class to use fancy rewriting prompt"""
         if not self.show_rewritten_input:
             return
 
         tokens = self.prompts.rewrite_prompt_tokens()
         if self.pt_app:
             print_formatted_text(PygmentsTokens(tokens), end='',
                                  style=self.pt_app.app.style)
             print(cmd)
         else:
             prompt = ''.join(s for t, s in tokens)
             print(prompt, cmd, sep='')
 
     _prompts_before = None
     def switch_doctest_mode(self, mode):
         """Switch prompts to classic for %doctest_mode"""
         if mode:
             self._prompts_before = self.prompts
             self.prompts = ClassicPrompts(self)
         elif self._prompts_before:
             self.prompts = self._prompts_before
             self._prompts_before = None
 #        self._update_layout()
 
 
 InteractiveShellABC.register(TerminalInteractiveShell)
 
 if __name__ == '__main__':
     TerminalInteractiveShell.instance().interact()

tools/gen_latex_symbols.py

@@ -1,92 +1,88 b''
 # coding: utf-8
 
 # This script autogenerates `IPython.core.latex_symbols.py`, which contains a
 # single dict , named `latex_symbols`. The keys in this dict are latex symbols,
 # such as `\\alpha` and the values in the dict are the unicode equivalents for
 # those. Most importantly, only unicode symbols that are valid identifiers in
 # Python 3 are included. 
 
 # 
 # The original mapping of latex symbols to unicode comes from the `latex_symbols.jl` files from Julia.
 
 import os, sys
 
-if sys.version_info[0] < 3:
-    print("This script must be run with Python 3, exiting...")
-    sys.exit(1)
-
 # Import the Julia LaTeX symbols
 print('Importing latex_symbols.js from Julia...')
 import requests
 url = 'https://raw.githubusercontent.com/JuliaLang/julia/master/stdlib/REPL/src/latex_symbols.jl'
 r = requests.get(url)
 
 
 # Build a list of key, value pairs
 print('Building a list of (latex, unicode) key-value pairs...')
 lines = r.text.splitlines()
 
 prefixes_line = lines.index('# "font" prefixes')
 symbols_line = lines.index('# manual additions:')
 
 prefix_dict = {}
 for l in lines[prefixes_line + 1: symbols_line]:
     p = l.split()
     if not p or p[1] == 'latex_symbols': continue
     prefix_dict[p[1]] = p[3]
 
 idents = []
 for l in lines[symbols_line:]:
     if not '=>' in l: continue # if it's not a def, skip
     if '#' in l: l = l[:l.index('#')] # get rid of eol comments
     x, y = l.strip().split('=>') 
     if '*' in x: # if a prefix is present substitute it with its value
         p, x = x.split('*')
         x = prefix_dict[p][:-1] + x[1:]
     x, y = x.split('"')[1], y.split('"')[1] # get the values in quotes
     idents.append((x, y))
 
 # Filter out non-valid identifiers
 print('Filtering out characters that are not valid Python 3 identifiers')
 
 def test_ident(i):
     """Is the unicode string valid in a Python 3 identifier."""
     # Some characters are not valid at the start of a name, but we still want to
     # include them. So prefix with 'a', which is valid at the start.
     return ('a' + i).isidentifier()
 
 assert test_ident("α")
 assert not test_ident('‴')
 
 valid_idents = [line for line in idents if test_ident(line[1])]
 
 # Write the `latex_symbols.py` module in the cwd
 
 s = """# encoding: utf-8
 
 # DO NOT EDIT THIS FILE BY HAND.
 
 # To update this file, run the script /tools/gen_latex_symbols.py using Python 3
 
 # This file is autogenerated from the file:
 # https://raw.githubusercontent.com/JuliaLang/julia/master/base/latex_symbols.jl
 # This original list is filtered to remove any unicode characters that are not valid
 # Python identifiers.
 
 latex_symbols = {\n
 """
 for line in valid_idents:
     s += '    "%s" : "%s",\n' % (line[0], line[1])
 s += "}\n"
 
 s += """
 
 reverse_latex_symbol = { v:k for k,v in latex_symbols.items()}
 """
 
 fn = os.path.join('..','IPython','core','latex_symbols.py')
 print("Writing the file: %s" % fn)
 with open(fn, 'w', encoding='utf-8') as f:
     f.write(s)