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# -*- coding: utf-8 -*-
"""Main IPython class."""
# Copyright (C) 2001 Janko Hauser <>
# Copyright (C) 2001-2007 Fernando Perez. <>
# 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.
# Imports
from __future__ import with_statement
from __future__ import absolute_import
import __builtin__
import __future__
import abc
import atexit
import codeop
import os
import re
import sys
import tempfile
import types
from contextlib import nested
from IPython.config.configurable import Configurable
from IPython.core import debugger, oinspect
from IPython.core import history as ipcorehist
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 AliasManager
from IPython.core.builtin_trap import BuiltinTrap
from IPython.core.compilerop import CachingCompiler
from IPython.core.display_trap import DisplayTrap
from IPython.core.displayhook import DisplayHook
from IPython.core.displaypub import DisplayPublisher
from IPython.core.error import TryNext, UsageError
from IPython.core.extensions import ExtensionManager
from IPython.core.fakemodule import FakeModule, init_fakemod_dict
from IPython.core.formatters import DisplayFormatter
from IPython.core.history import HistoryManager
from IPython.core.inputsplitter import IPythonInputSplitter
from IPython.core.logger import Logger
from IPython.core.magic import Magic
from IPython.core.payload import PayloadManager
from IPython.core.plugin import PluginManager
from IPython.core.prefilter import PrefilterManager, ESC_MAGIC
from IPython.external.Itpl import ItplNS
from IPython.utils import PyColorize
from IPython.utils import io
from IPython.utils.doctestreload import doctest_reload
from import ask_yes_no, rprint
from IPython.utils.ipstruct import Struct
from IPython.utils.path import get_home_dir, get_ipython_dir, HomeDirError
from IPython.utils.pickleshare import PickleShareDB
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 num_ini_spaces, format_screen, LSString, SList
from IPython.utils.traitlets import (Int, Str, CBool, CaselessStrEnum, Enum,
List, Unicode, Instance, Type)
from IPython.utils.warn import warn, error, fatal
import IPython.core.hooks
# Globals
# compiled regexps for autoindent management
dedent_re = re.compile(r'^\s+raise|^\s+return|^\s+pass')
# Utilities
# store the builtin raw_input globally, and use this always, in case user code
# overwrites it (like does)
raw_input_original = raw_input
def softspace(file, newvalue):
"""Copied from, to remove the dependency"""
oldvalue = 0
oldvalue = file.softspace
except AttributeError:
file.softspace = newvalue
except (AttributeError, TypeError):
# "attribute-less object" or "read-only attributes"
return oldvalue
def no_op(*a, **kw): pass
class SpaceInInput(Exception): pass
class Bunch: pass
def get_default_colors():
if sys.platform=='darwin':
return "LightBG"
return 'Linux'
return 'Linux'
class SeparateStr(Str):
"""A Str subclass to validate separate_in, separate_out, etc.
This is a Str based trait that converts '0'->'' and '\\n'->'\n'.
def validate(self, obj, value):
if value == '0': value = ''
value = value.replace('\\n','\n')
return super(SeparateStr, self).validate(obj, value)
class MultipleInstanceError(Exception):
# Main IPython class
class InteractiveShell(Configurable, Magic):
"""An enhanced, interactive shell for Python."""
_instance = None
autocall = Enum((0,1,2), default_value=1, config=True)
# 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)
automagic = CBool(True, config=True)
cache_size = Int(1000, config=True)
color_info = CBool(True, config=True)
colors = CaselessStrEnum(('NoColor','LightBG','Linux'),
default_value=get_default_colors(), config=True)
debug = CBool(False, config=True)
deep_reload = CBool(False, config=True)
display_formatter = Instance(DisplayFormatter)
displayhook_class = Type(DisplayHook)
display_pub_class = Type(DisplayPublisher)
exit_now = CBool(False)
# Monotonically increasing execution counter
execution_count = Int(1)
filename = Str("<ipython console>")
ipython_dir= Unicode('', config=True) # Set to get_ipython_dir() in __init__
# Input splitter, to split entire cells of input into either individual
# interactive statements or whole blocks.
input_splitter = Instance('IPython.core.inputsplitter.IPythonInputSplitter',
(), {})
logstart = CBool(False, config=True)
logfile = Str('', config=True)
logappend = Str('', config=True)
object_info_string_level = Enum((0,1,2), default_value=0,
pdb = CBool(False, config=True)
profile = Str('', config=True)
prompt_in1 = Str('In [\\#]: ', config=True)
prompt_in2 = Str(' .\\D.: ', config=True)
prompt_out = Str('Out[\\#]: ', config=True)
prompts_pad_left = CBool(True, config=True)
quiet = CBool(False, config=True)
history_length = Int(10000, config=True)
# 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_merge_completions = CBool(True, config=True)
readline_omit__names = Enum((0,1,2), default_value=2, config=True)
readline_remove_delims = Str('-/~', config=True)
readline_parse_and_bind = List([
'tab: complete',
'"\C-l": clear-screen',
'set show-all-if-ambiguous on',
'"\C-o": tab-insert',
# See bug gh-58 - with \M-i enabled, chars 0x9000-0x9fff
# crash IPython.
'"\M-o": "\d\d\d\d"',
'"\M-I": "\d\d\d\d"',
'"\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',
], allow_none=False, 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 = SeparateStr('\n', config=True)
separate_out = SeparateStr('', config=True)
separate_out2 = SeparateStr('', 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')
prefilter_manager = Instance('IPython.core.prefilter.PrefilterManager')
builtin_trap = Instance('IPython.core.builtin_trap.BuiltinTrap')
display_trap = Instance('IPython.core.display_trap.DisplayTrap')
extension_manager = Instance('IPython.core.extensions.ExtensionManager')
plugin_manager = Instance('IPython.core.plugin.PluginManager')
payload_manager = Instance('IPython.core.payload.PayloadManager')
history_manager = Instance('IPython.core.history.HistoryManager')
# Private interface
_post_execute = set()
def __init__(self, config=None, ipython_dir=None,
user_ns=None, user_global_ns=None,
custom_exceptions=((), None)):
# This is where traits with a config_key argument are updated
# from the values on config.
super(InteractiveShell, self).__init__(config=config)
# These are relatively independent and stateless
# Create namespaces (user_ns, user_global_ns, etc.)
self.init_create_namespaces(user_ns, user_global_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.
# 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.ipython_dir, 'db'))
Magic.__init__(self, self)
# self.init_traceback_handlers use to be here, but we moved it below
# because it and init_io have to come after init_readline.
# pre_config_initialization
# The next section should contain everything that was in ipmaker.
# The following was in post_config_initialization
# init_readline() must come before init_io(), because init_io uses
# readline related things.
# 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)
# 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.
def instance(cls, *args, **kwargs):
"""Returns a global InteractiveShell instance."""
if cls._instance is None:
inst = cls(*args, **kwargs)
# Now make sure that the instance will also be returned by
# the subclasses instance attribute.
for subclass in cls.mro():
if issubclass(cls, subclass) and \
issubclass(subclass, InteractiveShell):
subclass._instance = inst
if isinstance(cls._instance, cls):
return cls._instance
raise MultipleInstanceError(
'Multiple incompatible subclass instances of '
'InteractiveShell are being created.'
def initialized(cls):
return hasattr(cls, "_instance")
def get_ipython(self):
"""Return the currently running IPython instance."""
return self
# Trait changed handlers
def _ipython_dir_changed(self, name, new):
if not os.path.isdir(new):
os.makedirs(new, mode = 0777)
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 not self.has_readline:
if == 'posix':
warn("The auto-indent feature requires the readline library")
self.autoindent = 0
if value is None:
self.autoindent = not self.autoindent
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
self.config.Global.ipython_dir = self.ipython_dir
if hasattr(self.config.Global, 'ipython_dir'):
self.ipython_dir = self.config.Global.ipython_dir
self.ipython_dir = get_ipython_dir()
# All children can just read this
self.config.Global.ipython_dir = self.ipython_dir
def init_instance_attrs(self):
self.more = False
# command compiler
self.compile = CachingCompiler()
# User input buffers
# NOTE: these variables are slated for full removal, once we are 100%
# sure that the new execution logic is solid. We will delte runlines,
# push_line and these buffers, as all input will be managed by the
# frontends via an inputsplitter instance.
self.buffer = []
self.buffer_raw = []
# 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()
# Object variable to store code object waiting execution. This is
# used mainly by the multithreaded shells, but it can come in handy in
# other situations. No need to use a Queue here, since it's a single
# item which gets cleared once run.
self.code_to_run = None
# Temporary files used for various purposes. Deleted at exit.
self.tempfiles = []
# 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 = os.getcwd()
# Indentation management
self.indent_current_nsp = 0
def init_environment(self):
"""Any changes we need to make to the user's environment."""
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
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()
except HomeDirError, msg:
self.dir_stack = []
def init_logger(self):
self.logger = Logger(self.home_dir, logfname='',
def init_logstart(self):
"""Initialize logging in case it was requested at the command line.
if self.logappend:
self.magic_logstart(self.logappend + ' append')
elif self.logfile:
elif self.logstart:
def init_builtins(self):
self.builtin_trap = BuiltinTrap(shell=self)
def init_inspector(self):
# Object inspector
self.inspector = oinspect.Inspector(oinspect.InspectColors,
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 Term holds onto
# references to the underlying streams.
if sys.platform == 'win32' and self.has_readline:
Term = io.IOTerm(cout=self.readline._outputfile,
Term = io.IOTerm()
io.Term = Term
def init_prompts(self):
# TODO: This is a pass for now because the prompts are managed inside
# the DisplayHook. Once there is a separate prompt manager, this
# will initialize that object and all prompt related information.
def init_display_formatter(self):
self.display_formatter = DisplayFormatter(config=self.config)
def init_display_pub(self):
self.display_pub = self.display_pub_class(config=self.config)
def init_displayhook(self):
# Initialize displayhook, set in/out prompts and printing system
self.displayhook = self.displayhook_class(
input_sep = self.separate_in,
output_sep = self.separate_out,
output_sep2 = self.separate_out2,
ps1 = self.prompt_in1,
ps2 = self.prompt_in2,
ps_out = self.prompt_out,
pad_left = self.prompts_pad_left
# This is a context manager that installs/revmoes the displayhook at
# the appropriate time.
self.display_trap = DisplayTrap(hook=self.displayhook)
def init_reload_doctest(self):
# Do a proper resetting of doctest, including the necessary displayhook
# monkeypatching
except ImportError:
warn("doctest module does not exist.")
# 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_ns is created.
self._orig_sys_module_state = {}
self._orig_sys_module_state['stdin'] = sys.stdin
self._orig_sys_module_state['stdout'] = sys.stdout
self._orig_sys_module_state['stderr'] = sys.stderr
self._orig_sys_module_state['excepthook'] = sys.excepthook
self._orig_sys_modules_main_name = self.user_ns['__name__']
except KeyError:
def restore_sys_module_state(self):
"""Restore the state of the sys module."""
for k, v in self._orig_sys_module_state.iteritems():
setattr(sys, k, v)
except AttributeError:
# Reset what what done in self.init_sys_modules
sys.modules[self.user_ns['__name__']] = self._orig_sys_modules_main_name
except (AttributeError, KeyError):
# 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)
def set_hook(self,name,hook, priority = 50, str_key = None, re_key = None):
"""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
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
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 not dp:
dp = IPython.core.hooks.CommandChainDispatcher()
except AttributeError:
# it was not commandchain, plain old func - replace
dp = f
setattr(self.hooks,name, dp)
def register_post_execute(self, func):
"""Register a function for calling after code execution.
if not callable(func):
raise ValueError('argument %s must be callable' % func)
# Things related to the "main" module
def new_main_mod(self,ns=None):
"""Return a new 'main' module object for user code execution.
main_mod = self._user_main_module
return main_mod
def cache_main_mod(self,ns,fname):
"""Cache a main module's namespace.
When scripts are executed via %run, we must keep a reference to the
namespace of their __main__ module (a FakeModule instance) around so
that Python doesn't clear it, rendering objects defined therein
This method keeps said reference in a private dict, keyed by the
absolute path of the module object (which corresponds to the script
path). 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.
Note: we can not allow the actual FakeModule instances to be deleted,
because of how Python tears down modules (it hard-sets all their
references to None without regard for reference counts). This method
must therefore make a *copy* of the given namespace, to allow the
original module's __dict__ to be cleared and reused.
ns : a namespace (a dict, typically)
fname : str
Filename associated with the namespace.
In [10]: import IPython
In [11]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
In [12]: IPython.__file__ in _ip._main_ns_cache
Out[12]: True
self._main_ns_cache[os.path.abspath(fname)] = ns.copy()
def clear_main_mod_cache(self):
"""Clear the cache of main modules.
Mainly for use by utilities like %reset.
In [15]: import IPython
In [16]: _ip.cache_main_mod(IPython.__dict__,IPython.__file__)
In [17]: len(_ip._main_ns_cache) > 0
Out[17]: True
In [18]: _ip.clear_main_mod_cache()
In [19]: len(_ip._main_ns_cache) == 0
Out[19]: True
# 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.
- 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):
if not hasattr(sys,'last_traceback'):
error('No traceback has been produced, nothing to debug.')
# use pydb if available
if debugger.has_pydb:
from pydb import pm
# fallback to our internal debugger
pm = lambda : self.InteractiveTB.debugger(force=True)
# Things related to IPython's various namespaces
def init_create_namespaces(self, user_ns=None, user_global_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 <>
# Datum: Freitag 01 Oktober 2004 04:45:34 nachmittags/abends
# Gruppen: comp.lang.python
# Michael Hohn <> 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 properly built dicts as needed by the rest of
# the code, and can also be used by extension writers to generate
# properly initialized namespaces.
user_ns, user_global_ns = self.make_user_namespaces(user_ns,
# Assign namespaces
# This is the namespace where all normal user variables live
self.user_ns = user_ns
self.user_global_ns = user_global_ns
# An auxiliary namespace that checks what parts of the user_ns were
# loaded at startup, so we can list later only variables defined in
# actual interactive use. Since it is always a subset of user_ns, it
# doesn't need to be separately tracked in the ns_table.
self.user_ns_hidden = {}
# A namespace to keep track of internal data structures to prevent
# them from cluttering user-visible stuff. Will be updated later
self.internal_ns = {}
# 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 docetst 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_ns_cache = {}
# And this is the single instance of FakeModule whose __dict__ we keep
# copying and clearing for reuse on each %run
self._user_main_module = FakeModule()
# A table holding all the namespaces IPython deals with, so that
# introspection facilities can search easily.
self.ns_table = {'user':user_ns,
# Similarly, track all namespaces where references can be held and that
# we can safely clear (so it can NOT include builtin). This one can be
# a simple list. Note that the main execution namespaces, user_ns and
# user_global_ns, can NOT be listed here, as clearing them blindly
# causes errors in object __del__ methods. Instead, the reset() method
# clears them manually and carefully.
self.ns_refs_table = [ self.user_ns_hidden,
self.internal_ns, self._main_ns_cache ]
def make_user_namespaces(self, user_ns=None, user_global_ns=None):
"""Return a valid local and global user interactive namespaces.
This builds a dict with the minimal information needed to operate as a
valid IPython user namespace, which you can pass to the various
embedding classes in ipython. The default implementation returns the
same dict for both the locals and the globals to allow functions to
refer to variables in the namespace. Customized implementations can
return different dicts. The locals dictionary can actually be anything
following the basic mapping protocol of a dict, but the globals dict
must be a true dict, not even a subclass. It is recommended that any
custom object for the locals namespace synchronize with the globals
dict somehow.
Raises TypeError if the provided globals namespace is not a true dict.
user_ns : dict-like, optional
The current user namespace. The items in this namespace should
be included in the output. If None, an appropriate blank
namespace should be created.
user_global_ns : dict, optional
The current user global namespace. The items in this namespace
should be included in the output. If None, an appropriate
blank namespace should be created.
A pair of dictionary-like object to be used as the local namespace
of the interpreter and a dict to be used as the global namespace.
# We must ensure that __builtin__ (without the final 's') is always
# available and pointing to the __builtin__ *module*. For more details:
if user_ns is None:
# Set __name__ to __main__ to better match the behavior of the
# normal interpreter.
user_ns = {'__name__' :'__main__',
'__builtin__' : __builtin__,
'__builtins__' : __builtin__,
if user_global_ns is None:
user_global_ns = user_ns
if type(user_global_ns) is not dict:
raise TypeError("user_global_ns must be a true dict; got %r"
% type(user_global_ns))
return user_ns, user_global_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_ns['__name__']
except KeyError:
raise KeyError('user_ns dictionary MUST have a "__name__" key')
sys.modules[main_name] = FakeModule(self.user_ns)
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.
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
# 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 theye 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:
ns = dict(__builtin__ = __builtin__)
# Put 'help' in the user namespace
from site import _Helper
ns['help'] = _Helper()
except ImportError:
warn('help() not available - check')
# 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
# Sync what we've added so far to user_ns_hidden so these aren't seen
# by %who
# 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
def reset(self, new_session=True):
"""Clear all internal namespaces.
Note that this is much more aggressive than %reset, since it clears
fully all namespaces, as well as all input/output lists.
If new_session is True, a new history session will be opened.
# Clear histories
# Reset counter used to index all histories
self.execution_count = 0
# Restore the user namespaces to minimal usability
for ns in self.ns_refs_table:
# 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.
for ns in [self.user_ns, self.user_global_ns]:
drop_keys = set(ns.keys())
for k in drop_keys:
del ns[k]
# Restore the user namespaces to minimal usability
# Restore the default and user aliases
def reset_selective(self, regex=None):
"""Clear selective variables from internal namespaces based on a
specified regular expression.
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:
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.ns_refs_table:
for var in ns:
del ns[var]
def push(self, variables, interactive=True):
"""Inject a group of variables into the IPython user namespace.
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``
vdict = None
# We need a dict of name/value pairs to do namespace updates.
if isinstance(variables, dict):
vdict = variables
elif isinstance(variables, (basestring, list, tuple)):
if isinstance(variables, basestring):
vlist = variables.split()
vlist = variables
vdict = {}
cf = sys._getframe(1)
for name in vlist:
vdict[name] = eval(name, cf.f_globals, cf.f_locals)
print ('Could not get variable %s from %s' %
raise ValueError('variables must be a dict/str/list/tuple')
# Propagate variables to user namespace
# And configure interactive visibility
config_ns = self.user_ns_hidden
if interactive:
for name, val in vdict.iteritems():
config_ns.pop(name, None)
for name,val in vdict.iteritems():
config_ns[name] = val
# 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
oname = oname.strip().encode('ascii')
#print '2- oname: <%r>' % oname # dbg
except UnicodeEncodeError:
print 'Python identifiers can only contain ascii characters.'
return dict(found=False)
alias_ns = None
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),
('IPython internal', self.internal_ns),
('Python builtin', __builtin__.__dict__),
('Alias', self.alias_manager.alias_table),
alias_ns = self.alias_manager.alias_table
# initialize results to 'null'
found = False; obj = None; ospace = None; ds = 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 (self.compile.compiler_flags &
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:
obj = ns[oname_head]
except KeyError:
#print 'oname_rest:', oname_rest # dbg
for part in oname_rest:
parent = obj
obj = getattr(obj,part)
# Blanket except b/c some badly implemented objects
# allow __getattr__ to raise exceptions other than
# AttributeError, which then crashes IPython.
# If we finish the for loop (no break), we got all members
found = True
ospace = nsname
if ns == alias_ns:
isalias = True
break # namespace loop
# Try to see if it's magic
if not found:
if oname.startswith(ESC_MAGIC):
oname = oname[1:]
obj = getattr(self,'magic_'+oname,None)
if obj is not None:
found = True
ospace = 'IPython internal'
ismagic = True
# 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}
def _ofind_property(self, oname, info):
"""Second part of object finding, to look for property details."""
if info.found:
# Get the docstring of the class property if it exists.
path = oname.split('.')
root = '.'.join(path[:-1])
if info.parent is not None:
target = getattr(info.parent, '__class__')
# The object belongs to a class instance.
target = getattr(target, path[-1])
# The class defines the object.
if isinstance(target, property):
oname = root + '.__class__.' + path[-1]
info = Struct(self._ofind(oname))
except AttributeError: pass
except AttributeError: pass
# We return either the new info or the unmodified input if the object
# hadn't been found
return info
def _object_find(self, oname, namespaces=None):
"""Find an object and return a struct with info about it."""
inf = Struct(self._ofind(oname, namespaces))
return Struct(self._ofind_property(oname, inf))
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)
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)
pmethod(info.obj, oname)
print 'Object `%s` not found.' % oname
return 'not found' # so callers can take other action
def object_inspect(self, oname):
info = self._object_find(oname)
if info.found:
return, oname, info=info)
return oinspect.object_info(name=oname, found=False)
# Things related to history management
def init_history(self):
"""Sets up the command history, and starts regular autosaves."""
self.history_manager = HistoryManager(shell=self, config=self.config)
def history_saving_wrapper(self, func):
""" Wrap func for readline history saving
Convert func into callable that saves & restores
history around the call """
if self.has_readline:
from IPython.utils import rlineimpl as readline
return func
def wrapper():
return wrapper
# 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',
tb_offset = 1,
# 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
# Set the exception mode
def set_custom_exc(self, 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.
- exc_tuple: a *tuple* of valid exceptions to call the defined
handler for. 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: this must be defined as a function with the following
basic interface::
def my_handler(self, etype, value, tb, tb_offset=None)
# The return value must be
return structured_traceback
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.
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):
print '*** Simple custom exception handler ***'
print 'Exception type :',etype
print 'Exception value:',value
print 'Traceback :',tb
print 'Source code :','\n'.join(self.buffer)
if handler is None: handler = dummy_handler
self.CustomTB = types.MethodType(handler,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
This hook should be used sparingly, only in places which are not likely
to be true IPython errors.
def showtraceback(self,exc_tuple = None,filename=None,tb_offset=None,
"""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."""
if exc_tuple is None:
etype, value, tb = sys.exc_info()
etype, value, tb = exc_tuple
if etype is None:
if hasattr(sys, 'last_type'):
etype, value, tb = sys.last_type, sys.last_value, \
self.write_err('No traceback available to show.\n')
if etype is SyntaxError:
# Though this won't be called by syntax errors in the input
# line, there may be SyntaxError cases whith imported code.
elif etype is UsageError:
print "UsageError:", value
# 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
if etype in self.custom_exceptions:
# FIXME: Old custom traceback objects may just return a
# string, in that case we just put it into a list
stb = self.CustomTB(etype, value, tb, tb_offset)
if isinstance(ctb, basestring):
stb = [stb]
if exception_only:
stb = ['An exception has occurred, use %tb to see '
'the full traceback.\n']
stb = self.InteractiveTB.structured_traceback(etype,
value, tb, tb_offset=tb_offset)
# FIXME: the pdb calling should be done by us, not by
# the code computing the traceback.
if self.InteractiveTB.call_pdb:
# pdb mucks up readline, fix it back
# Actually show the traceback
self._showtraceback(etype, value, stb)
except KeyboardInterrupt:
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 >> io.Term.cout, self.InteractiveTB.stb2text(stb)
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 = sys.exc_info()
# See note about these variables in showtraceback() above
sys.last_type = etype
sys.last_value = value
sys.last_traceback = last_traceback
if filename and etype is SyntaxError:
# Work hard to stuff the correct filename in the exception
msg, (dummy_filename, lineno, offset, line) = value
# Not the format we expect; leave it alone
# Stuff in the right filename
# Assume SyntaxError is a class exception
value = SyntaxError(msg, (filename, lineno, offset, line))
# If that failed, assume SyntaxError is a string
value = msg, (filename, lineno, offset, line)
stb = self.SyntaxTB.structured_traceback(etype, value, [])
self._showtraceback(etype, value, stb)
# Things related to readline
def init_readline(self):
"""Command history completion/saving/reloading."""
if self.readline_use:
import IPython.utils.rlineimpl as readline
self.rl_next_input = None
self.rl_do_indent = False
if not self.readline_use or not readline.have_readline:
self.has_readline = False
self.readline = None
# Set a number of methods that depend on readline to be no-op
self.set_readline_completer = no_op
self.set_custom_completer = no_op
self.set_completer_frame = no_op
warn('Readline services not available or not loaded.')
self.has_readline = True
self.readline = readline
sys.modules['readline'] = readline
# Platform-specific configuration
if == 'nt':
# FIXME - check with Frederick to see if we can harmonize
# naming conventions with pyreadline to avoid this
# platform-dependent check
self.readline_startup_hook = readline.set_pre_input_hook
self.readline_startup_hook = readline.set_startup_hook
# Load user's initrc file (readline config)
# Or if libedit is used, load editrc.
inputrc_name = os.environ.get('INPUTRC')
if inputrc_name is None:
home_dir = get_home_dir()
if home_dir is not None:
inputrc_name = '.inputrc'
if readline.uses_libedit:
inputrc_name = '.editrc'
inputrc_name = os.path.join(home_dir, inputrc_name)
if os.path.isfile(inputrc_name):
warn('Problems reading readline initialization file <%s>'
% inputrc_name)
# Configure readline according to user's prefs
# This is only done if GNU readline is being used. If libedit
# is being used (as on Leopard) the readline config is
# not run as the syntax for libedit is different.
if not readline.uses_libedit:
for rlcommand in self.readline_parse_and_bind:
#print "loading rl:",rlcommand # dbg
# Remove some chars from the delimiters list. If we encounter
# unicode chars, discard them.
delims = readline.get_completer_delims().encode("ascii", "ignore")
delims = delims.translate(None, self.readline_remove_delims)
delims = delims.replace(ESC_MAGIC, '')
# otherwise we end up with a monster history after a while:
stdin_encoding = sys.stdin.encoding or "utf-8"
# Load the last 1000 lines from history
for _, _, cell in self.history_manager.get_tail(1000,
if cell.strip(): # Ignore blank lines
for line in cell.splitlines():
# Configure auto-indent for all platforms
def set_next_input(self, s):
""" Sets the 'default' input string for the next command line.
Requires readline.
[D:\ipython]|1> _ip.set_next_input("Hello Word")
[D:\ipython]|2> Hello Word_ # cursor is here
self.rl_next_input = s
# Maybe move this to the terminal subclass?
def pre_readline(self):
"""readline hook to be used at the start of each line.
Currently it handles auto-indent only."""
if self.rl_do_indent:
if self.rl_next_input is not None:
self.rl_next_input = None
def _indent_current_str(self):
"""return the current level of indentation as a string"""
return self.input_splitter.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), programatically (such as in test suites) or out-of-prcess
(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)
self.Completer = IPCompleter(self,
# 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', magic_run_completer, str_key = '%run')
self.set_hook('complete_command', cd_completer, str_key = '%cd')
# Only configure readline if we truly are using readline. IPython can
# do tab-completion over the network, in GUIs, etc, where readline
# itself may be absent
if self.has_readline:
def complete(self, text, line=None, cursor_pos=None):
"""Return the completed text and a list of completions.
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.
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)
def set_readline_completer(self):
"""Reset readline's completer to be our own."""
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
self.Completer.namespace = self.user_ns
self.Completer.global_namespace = self.user_global_ns
# Things related to magics
def init_magics(self):
# 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.
# History was moved to a separate module
from . import history
def magic(self,arg_s):
"""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
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.
args = arg_s.split(' ',1)
magic_name = args[0]
magic_name = magic_name.lstrip(prefilter.ESC_MAGIC)
magic_args = args[1]
except IndexError:
magic_args = ''
fn = getattr(self,'magic_'+magic_name,None)
if fn is None:
error("Magic function `%s` not found." % magic_name)
magic_args = self.var_expand(magic_args,1)
with nested(self.builtin_trap,):
result = fn(magic_args)
return result
def define_magic(self, magicname, func):
"""Expose own function as magic function for ipython
def foo_impl(self,parameter_s=''):
'My very own magic!. (Use docstrings, IPython reads them).'
print 'Magic function. Passed parameter is between < >:'
print '<%s>' % parameter_s
print 'The self object is:',self
import new
im = types.MethodType(func,self)
old = getattr(self, "magic_" + magicname, None)
setattr(self, "magic_" + magicname, im)
return old
# Things related to macros
def define_macro(self, name, themacro):
"""Define a new macro
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, basestring):
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(self, cmd):
"""Call the given cmd in a subprocess.
cmd : str
Command to execute (can not end in '&', as bacground processes are
not supported.
# We do not support backgrounding processes because we either use
# pexpect or pipes to read from. Users can always just call
# os.system() if they really want a background process.
if cmd.endswith('&'):
raise OSError("Background processes not supported.")
return system(self.var_expand(cmd, depth=2))
def getoutput(self, cmd, split=True):
"""Get output (possibly including stderr) from a subprocess.
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
if cmd.endswith('&'):
raise OSError("Background processes not supported.")
out = getoutput(self.var_expand(cmd, depth=2))
if split:
out = SList(out.splitlines())
out = LSString(out)
return out
# Things related to aliases
def init_alias(self):
self.alias_manager = AliasManager(shell=self, config=self.config)
self.ns_table['alias'] = self.alias_manager.alias_table,
# Things related to extensions and plugins
def init_extension_manager(self):
self.extension_manager = ExtensionManager(shell=self, config=self.config)
def init_plugin_manager(self):
self.plugin_manager = PluginManager(config=self.config)
# Things related to payloads
def init_payload(self):
self.payload_manager = PayloadManager(config=self.config)
# Things related to the prefilter
def init_prefilter(self):
self.prefilter_manager = PrefilterManager(shell=self, config=self.config)
# 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
------> f(x)
after the user's input prompt. This helps the user understand that the
input line was transformed automatically by IPython.
rw = self.displayhook.prompt1.auto_rewrite() + cmd
# plain ascii works better w/ pyreadline, on some machines, so
# we use it and only print uncolored rewrite if we have unicode
rw = str(rw)
print >>, rw
except UnicodeEncodeError:
print "------> " + cmd
# Things related to extracting values/expressions from kernel and user_ns
def _simple_error(self):
etype, value = sys.exc_info()[:2]
return u'[ERROR] {e.__name__}: {v}'.format(e=etype, v=value)
def user_variables(self, names):
"""Get a list of variable names from the user's namespace.
names : list of strings
A list of names of variables to be read from the user namespace.
A dict, keyed by the input names and with the repr() of each value.
out = {}
user_ns = self.user_ns
for varname in names:
value = repr(user_ns[varname])
value = self._simple_error()
out[varname] = value
return out
def user_expressions(self, expressions):
"""Evaluate a dict of expressions in the user's namespace.
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.
A dict, keyed like the input expressions dict, with the repr() of each
out = {}
user_ns = self.user_ns
global_ns = self.user_global_ns
for key, expr in expressions.iteritems():
value = repr(eval(expr, global_ns, user_ns))
value = self._simple_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 nested(self.builtin_trap,):
exec cmd in self.user_global_ns, self.user_ns
def ev(self, expr):
"""Evaluate python expression expr in user namespace.
Returns the result of evaluation
with nested(self.builtin_trap,):
return eval(expr, self.user_global_ns, self.user_ns)
def safe_execfile(self, fname, *where, **kw):
"""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.
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).
kw.setdefault('exit_ignore', False)
fname = os.path.abspath(os.path.expanduser(fname))
# Make sure we have a .py file
if not fname.endswith('.py'):
warn('File must end with .py to be run using execfile: <%s>' % fname)
# Make sure we can open the file
with open(fname) as thefile:
warn('Could not open file <%s> for safe execution.' % fname)
# 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):
except SystemExit, 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 not in (0, None) and not kw['exit_ignore']:
def safe_execfile_ipy(self, fname):
"""Like safe_execfile, but for .ipy files with IPython syntax.
fname : str
The name of the file to execute. The filename must have a
.ipy extension.
fname = os.path.abspath(os.path.expanduser(fname))
# Make sure we have a .py file
if not fname.endswith('.ipy'):
warn('File must end with .py to be run using execfile: <%s>' % fname)
# Make sure we can open the file
with open(fname) as thefile:
warn('Could not open file <%s> for safe execution.' % fname)
# 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):
with open(fname) as thefile:
# self.run_cell currently captures all exceptions
# raised in user code. It would be nice if there were
# versions of runlines, execfile that did raise, so
# we could catch the errors.
warn('Unknown failure executing file: <%s>' % fname)
def run_cell(self, cell, store_history=True):
"""Run the contents of an entire multiline 'cell' of code, and store it
in the history.
The cell is split into separate blocks which can be executed
individually. Then, based on how many blocks there are, they are
executed as follows:
- A single block: 'single' mode. If it is also a single line, dynamic
transformations, including automagic and macros, will be applied.
If there's more than one block, it depends:
- if the last one is no more than two lines long, run all but the last
in 'exec' mode and the very last one in 'single' mode. This makes it
easy to type simple expressions at the end to see computed values. -
otherwise (last one is also multiline), run all in 'exec' mode
When code is executed in 'single' mode, :func:`sys.displayhook` fires,
results are displayed and output prompts are computed. In 'exec' mode,
no results are displayed unless :func:`print` is called explicitly;
this mode is more akin to running a script.
cell : str
A single or multiline string.