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Simplified output stream management in ultratb....
Simplified output stream management in ultratb. This lets us have one less hack in the testing globalipapp code, as well as rationalizing the ultratb code a little more. There is now an ostream property for all output that can be used consistently.

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builtin_trap.py
115 lines | 3.9 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
# encoding: utf-8
"""
A context manager for managing things injected into :mod:`__builtin__`.
Authors:
* Brian Granger
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2009 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
#-----------------------------------------------------------------------------
import __builtin__
from IPython.config.configurable import Configurable
from IPython.core.quitter import Quitter
from IPython.utils.traitlets import Instance
#-----------------------------------------------------------------------------
# Classes and functions
#-----------------------------------------------------------------------------
class __BuiltinUndefined(object): pass
BuiltinUndefined = __BuiltinUndefined()
class BuiltinTrap(Configurable):
shell = Instance('IPython.core.interactiveshell.InteractiveShellABC')
def __init__(self, shell=None):
super(BuiltinTrap, self).__init__(shell=shell, config=None)
self._orig_builtins = {}
# We define this to track if a single BuiltinTrap is nested.
# Only turn off the trap when the outermost call to __exit__ is made.
self._nested_level = 0
self.shell = shell
def __enter__(self):
if self._nested_level == 0:
self.set()
self._nested_level += 1
# I return self, so callers can use add_builtin in a with clause.
return self
def __exit__(self, type, value, traceback):
if self._nested_level == 1:
self.unset()
self._nested_level -= 1
# Returning False will cause exceptions to propagate
return False
def add_builtin(self, key, value):
"""Add a builtin and save the original."""
orig = __builtin__.__dict__.get(key, BuiltinUndefined)
self._orig_builtins[key] = orig
__builtin__.__dict__[key] = value
def remove_builtin(self, key):
"""Remove an added builtin and re-set the original."""
try:
orig = self._orig_builtins.pop(key)
except KeyError:
pass
else:
if orig is BuiltinUndefined:
del __builtin__.__dict__[key]
else:
__builtin__.__dict__[key] = orig
def set(self):
"""Store ipython references in the __builtin__ namespace."""
self.add_builtin('exit', Quitter(self.shell, 'exit'))
self.add_builtin('quit', Quitter(self.shell, 'quit'))
self.add_builtin('get_ipython', self.shell.get_ipython)
# Recursive reload function
try:
from IPython.lib import deepreload
if self.shell.deep_reload:
self.add_builtin('reload', deepreload.reload)
else:
self.add_builtin('dreload', deepreload.reload)
del deepreload
except ImportError:
pass
# Keep in the builtins a flag for when IPython is active. We set it
# with setdefault so that multiple nested IPythons don't clobber one
# another. Each will increase its value by one upon being activated,
# which also gives us a way to determine the nesting level.
__builtin__.__dict__.setdefault('__IPYTHON__active',0)
def unset(self):
"""Remove any builtins which might have been added by add_builtins, or
restore overwritten ones to their previous values."""
for key in self._orig_builtins.keys():
self.remove_builtin(key)
self._orig_builtins.clear()
self._builtins_added = False
try:
del __builtin__.__dict__['__IPYTHON__active']
except KeyError:
pass