Replace all import of IPython.utils.warn module
Replace all import of IPython.utils.warn module

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interactiveshell.py
3242 lines | 129.5 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""Main IPython class."""
#-----------------------------------------------------------------------------
# Copyright (C) 2001 Janko Hauser <jhauser@zscout.de>
# Copyright (C) 2001-2007 Fernando Perez. <fperez@colorado.edu>
# 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.
#-----------------------------------------------------------------------------
from __future__ import absolute_import, print_function
import __future__
import abc
import ast
import atexit
import functools
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 IPython.core import debugger, oinspect
from IPython.core import magic
from IPython.core import page
from IPython.core import prefilter
from IPython.core import shadowns
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.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.inputsplitter import IPythonInputSplitter, 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.prompts import PromptManager
from IPython.core.usage import default_banner
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.contexts import NoOpContext
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, unquote_filename, ensure_dir_exists
from IPython.utils.process import system, getoutput
from IPython.utils.py3compat import (builtin_mod, unicode_type, string_types,
with_metaclass, iteritems)
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 traitlets import (Integer, Bool, CBool, CaselessStrEnum, Enum,
List, Dict, Unicode, Instance, Type)
from warnings import warn
from logging import error
import IPython.core.hooks
#-----------------------------------------------------------------------------
# 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
@undoc
class Bunch: pass
def get_default_colors():
if sys.platform=='darwin':
return "LightBG"
elif os.name=='nt':
return 'Linux'
else:
return 'Linux'
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__."""
pass
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
result = None
@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
class InteractiveShell(SingletonConfigurable):
"""An enhanced, interactive shell for Python."""
_instance = None
ast_transformers = List([], config=True, help=
"""
A list of ast.NodeTransformer subclass instances, which will be applied
to user input before code is run.
"""
)
autocall = Enum((0,1,2), default_value=0, config=True, 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).
"""
)
# TODO: remove all autoindent logic and put into frontends.
# We can't do this yet because even runlines uses the autoindent.
autoindent = CBool(True, config=True, help=
"""
Autoindent IPython code entered interactively.
"""
)
automagic = CBool(True, config=True, help=
"""
Enable magic commands to be called without the leading %.
"""
)
banner1 = Unicode(default_banner, config=True,
help="""The part of the banner to be printed before the profile"""
)
banner2 = Unicode('', config=True,
help="""The part of the banner to be printed after the profile"""
)
cache_size = Integer(1000, config=True, 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 20 (if
you provide a value less than 20, 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
"""
)
color_info = CBool(True, config=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.
"""
)
colors = CaselessStrEnum(('NoColor','LightBG','Linux'),
default_value=get_default_colors(), config=True,
help="Set the color scheme (NoColor, Linux, or LightBG)."
)
colors_force = CBool(False, help=
"""
Force use of ANSI color codes, regardless of OS and readline
availability.
"""
# FIXME: This is essentially a hack to allow ZMQShell to show colors
# without readline on Win32. When the ZMQ formatting system is
# refactored, this should be removed.
)
debug = CBool(False, config=True)
deep_reload = CBool(False, config=True, help=
"""
**Deprecated**
Will be removed in IPython 6.0
Enable deep (recursive) reloading by default. IPython can use the
deep_reload module which reloads changes in modules recursively (it
replaces the reload() function, so you don't need to change anything to
use it). `deep_reload` forces a full reload of modules whose code may
have changed, which the default reload() function does not. When
deep_reload is off, IPython will use the normal reload(), but
deep_reload will still be available as dreload().
"""
)
disable_failing_post_execute = CBool(False, config=True,
help="Don't call post-execute functions that have failed in the past."
)
display_formatter = Instance(DisplayFormatter, allow_none=True)
displayhook_class = Type(DisplayHook)
display_pub_class = Type(DisplayPublisher)
data_pub_class = None
exit_now = CBool(False)
exiter = Instance(ExitAutocall)
def _exiter_default(self):
return ExitAutocall(self)
# Monotonically increasing execution counter
execution_count = Integer(1)
filename = Unicode("<ipython console>")
ipython_dir= Unicode('', config=True) # Set to get_ipython_dir() in __init__
# Input splitter, to transform input line by line and detect when a block
# is ready to be executed.
input_splitter = Instance('IPython.core.inputsplitter.IPythonInputSplitter',
(), {'line_input_checker': True})
# This InputSplitter instance is used to transform completed cells before
# running them. It allows cell magics to contain blank lines.
input_transformer_manager = Instance('IPython.core.inputsplitter.IPythonInputSplitter',
(), {'line_input_checker': False})
logstart = CBool(False, config=True, help=
"""
Start logging to the default log file in overwrite mode.
Use `logappend` to specify a log file to **append** logs to.
"""
)
logfile = Unicode('', config=True, help=
"""
The name of the logfile to use.
"""
)
logappend = Unicode('', config=True, help=
"""
Start logging to the given file in append mode.
Use `logfile` to specify a log file to **overwrite** logs to.
"""
)
object_info_string_level = Enum((0,1,2), default_value=0,
config=True)
pdb = CBool(False, config=True, help=
"""
Automatically call the pdb debugger after every exception.
"""
)
multiline_history = CBool(sys.platform != 'win32', config=True,
help="Save multi-line entries as one entry in readline history"
)
display_page = Bool(False, config=True,
help="""If True, anything that would be passed to the pager
will be displayed as regular output instead."""
)
# deprecated prompt traits:
prompt_in1 = Unicode('In [\\#]: ', config=True,
help="Deprecated, will be removed in IPython 5.0, use PromptManager.in_template")
prompt_in2 = Unicode(' .\\D.: ', config=True,
help="Deprecated, will be removed in IPython 5.0, use PromptManager.in2_template")
prompt_out = Unicode('Out[\\#]: ', config=True,
help="Deprecated, will be removed in IPython 5.0, use PromptManager.out_template")
prompts_pad_left = CBool(True, config=True,
help="Deprecated, will be removed in IPython 5.0, use PromptManager.justify")
def _prompt_trait_changed(self, name, old, new):
table = {
'prompt_in1' : 'in_template',
'prompt_in2' : 'in2_template',
'prompt_out' : 'out_template',
'prompts_pad_left' : 'justify',
}
warn("InteractiveShell.{name} is deprecated, use PromptManager.{newname}".format(
name=name, newname=table[name])
)
# protect against weird cases where self.config may not exist:
if self.config is not None:
# propagate to corresponding PromptManager trait
setattr(self.config.PromptManager, table[name], new)
_prompt_in1_changed = _prompt_trait_changed
_prompt_in2_changed = _prompt_trait_changed
_prompt_out_changed = _prompt_trait_changed
_prompt_pad_left_changed = _prompt_trait_changed
show_rewritten_input = CBool(True, config=True,
help="Show rewritten input, e.g. for autocall."
)
quiet = CBool(False, config=True)
history_length = Integer(10000, config=True)
history_load_length = Integer(1000, config=True, help=
"""
The number of saved history entries to be loaded
into the readline buffer at startup.
"""
)
# The readline stuff will eventually be moved to the terminal subclass
# but for now, we can't do that as readline is welded in everywhere.
readline_use = CBool(True, config=True)
readline_remove_delims = Unicode('-/~', config=True)
readline_delims = Unicode() # set by init_readline()
# don't use \M- bindings by default, because they
# conflict with 8-bit encodings. See gh-58,gh-88
readline_parse_and_bind = List([
'tab: complete',
'"\C-l": clear-screen',
'set show-all-if-ambiguous on',
'"\C-o": tab-insert',
'"\C-r": reverse-search-history',
'"\C-s": forward-search-history',
'"\C-p": history-search-backward',
'"\C-n": history-search-forward',
'"\e[A": history-search-backward',
'"\e[B": history-search-forward',
'"\C-k": kill-line',
'"\C-u": unix-line-discard',
], config=True)
_custom_readline_config = False
def _readline_parse_and_bind_changed(self, name, old, new):
# notice that readline config is customized
# indicates that it should have higher priority than inputrc
self._custom_readline_config = True
ast_node_interactivity = Enum(['all', 'last', 'last_expr', 'none'],
default_value='last_expr', config=True,
help="""
'all', 'last', 'last_expr' or 'none', specifying which nodes should be
run interactively (displaying output from expressions).""")
# 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', config=True)
separate_out = SeparateUnicode('', config=True)
separate_out2 = SeparateUnicode('', config=True)
wildcards_case_sensitive = CBool(True, config=True)
xmode = CaselessStrEnum(('Context','Plain', 'Verbose'),
default_value='Context', 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
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)
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_traceback_handlers use to be here, but we moved it below
# because it and init_io have to come after init_readline.
self.init_user_ns()
self.init_logger()
self.init_builtins()
# The following was in post_config_initialization
self.init_inspector()
# init_readline() must come before init_io(), because init_io uses
# readline related things.
self.init_readline()
# We save this here in case user code replaces raw_input, but it needs
# to be after init_readline(), because PyPy's readline works by replacing
# raw_input.
if py3compat.PY3:
self.raw_input_original = input
else:
self.raw_input_original = raw_input
# init_completer must come after init_readline, because it needs to
# know whether readline is present or not system-wide to configure the
# completers, since the completion machinery can now operate
# independently of readline (e.g. over the network)
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
#-------------------------------------------------------------------------
def _ipython_dir_changed(self, name, new):
ensure_dir_exists(new)
def set_autoindent(self,value=None):
"""Set the autoindent flag, checking for readline support.
If called with no arguments, it acts as a toggle."""
if value != 0 and not self.has_readline:
if os.name == 'posix':
warn("The auto-indent feature requires the readline library")
self.autoindent = 0
return
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 readline usage (later set by init_readline)
self.has_readline = False
# keep track of where we started running (mainly for crash post-mortem)
# This is not being used anywhere currently.
self.starting_dir = py3compat.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'
def init_syntax_highlighting(self):
# Python source parser/formatter for syntax highlighting
pyformat = PyColorize.Parser().format
self.pycolorize = lambda src: pyformat(src,'str',self.colors)
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.
"""
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
# In 0.11 we introduced '__IPYTHON__active' as an integer we'd try to
# manage on enter/exit, but with all our shells it's virtually
# impossible to get all the cases right. We're leaving the name in for
# those who adapted their codes to check for this flag, but will
# eventually remove it after a few more releases.
builtin_mod.__dict__['__IPYTHON__active'] = \
'Deprecated, check for __IPYTHON__'
self.builtin_trap = BuiltinTrap(shell=self)
def init_inspector(self):
# Object inspector
self.inspector = oinspect.Inspector(oinspect.InspectColors,
PyColorize.ANSICodeColors,
'NoColor',
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.
if (sys.platform == 'win32' or sys.platform == 'cli') and self.has_readline:
io.stdout = io.stderr = io.IOStream(self.readline._outputfile)
else:
io.stdout = io.IOStream(sys.stdout)
io.stderr = io.IOStream(sys.stderr)
def init_prompts(self):
self.prompt_manager = PromptManager(shell=self, parent=self)
self.configurables.append(self.prompt_manager)
# 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
# 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)
p = os.path.normcase(sys.executable)
paths = [p]
while os.path.islink(p):
p = os.path.normcase(os.path.join(os.path.dirname(p), os.readlink(p)))
paths.append(p)
p_venv = os.path.normcase(os.environ['VIRTUAL_ENV'])
if any(p.startswith(p_venv) 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 iteritems(self._orig_sys_module_state):
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
self.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))
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.")
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(
py3compat.cast_bytes_py2(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 pydb/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
# use pydb if available
if debugger.has_pydb:
from pydb import pm
else:
# fallback to our internal debugger
pm = lambda : self.InteractiveTB.debugger(force=True)
with self.readline_no_record:
pm()
#-------------------------------------------------------------------------
# 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 <aleaxit@yahoo.com>
# Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
# Gruppen: comp.lang.python
# Michael Hohn <hohn@hooknose.lbl.gov> 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
therm.
"""
# 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 = dict()
# 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
ns['_sh'] = shadowns
# 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
# 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()
# 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 iteritems(ns) if o is obj]
for name in to_delete:
del ns[name]
# 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, string_types+(list, tuple)):
if isinstance(variables, string_types):
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 iteritems(variables):
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()
#print '1- oname: <%r>' % oname # dbg
if not oname.startswith(ESC_MAGIC) and \
not oname.startswith(ESC_MAGIC2) and \
not py3compat.isidentifier(oname, dotted=True):
return dict(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__),
]
# initialize results to 'null'
found = False; obj = None; ospace = None;
ismagic = False; isalias = False; parent = None
# We need to special-case 'print', which as of python2.6 registers as a
# function but should only be treated as one if print_function was
# loaded with a future import. In this case, just bail.
if (oname == 'print' and not py3compat.PY3 and not \
(self.compile.compiler_flags & __future__.CO_FUTURE_PRINT_FUNCTION)):
return {'found':found, 'obj':obj, 'namespace':ospace,
'ismagic':ismagic, 'isalias':isalias, 'parent':parent}
# 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:
#print 'oname_rest:', oname_rest # dbg
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 {'found':found, 'obj':obj, 'namespace':ospace,
'ismagic':ismagic, 'isalias':isalias, 'parent':parent}
@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)
if info.found:
pmethod = getattr(self.inspector, meth)
formatter = format_screen if info.ismagic else None
if meth == 'pdoc':
pmethod(info.obj, oname, formatter)
elif meth == 'pinfo':
pmethod(info.obj, oname, formatter, info, **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"""
with self.builtin_trap:
info = self._object_find(oname)
if info.found:
return self.inspector._format_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)
#-------------------------------------------------------------------------
def init_traceback_handlers(self, custom_exceptions):
# Syntax error handler.
self.SyntaxTB = ultratb.SyntaxTB(color_scheme='NoColor')
# 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']
self.InteractiveTB = ultratb.AutoFormattedTB(mode = 'Plain',
color_scheme='NoColor',
tb_offset = 1,
check_cache=check_linecache_ipython)
# 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."""
assert type(exc_tuple)==type(()) , \
"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)
#print 'Source code :','\n'.join(self.buffer)
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, string_types):
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, string_types):
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=io.stderr)
# show the exception in handler first
stb = self.InteractiveTB.structured_traceback(*sys.exc_info())
print(self.InteractiveTB.stb2text(stb), file=io.stdout)
print("The original exception:", file=io.stdout)
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.
"""
self.write_err("UsageError: %s" % exc)
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):
"""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:
self.write_err('No traceback available to show.\n')
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)
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:
self.write_err('\n' + self.get_exception_only())
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), file=io.stdout)
def showsyntaxerror(self, filename=None):
"""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).
"""
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
stb = self.SyntaxTB.structured_traceback(etype, value, [])
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):
"""Moved to terminal subclass, here only to simplify the init logic."""
self.readline = None
# Set a number of methods that depend on readline to be no-op
self.readline_no_record = NoOpContext()
self.set_readline_completer = no_op
self.set_custom_completer = no_op
@skip_doctest
def set_next_input(self, s,