|
|
# encoding: utf-8
|
|
|
"""
|
|
|
Context managers for adding things to sys.path temporarily.
|
|
|
|
|
|
Authors:
|
|
|
|
|
|
* Brian Granger
|
|
|
"""
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# 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
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
import sys
|
|
|
|
|
|
from IPython.utils.py3compat import cast_bytes_py2
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# Code
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
class appended_to_syspath(object):
|
|
|
"""A context for appending a directory to sys.path for a second."""
|
|
|
|
|
|
def __init__(self, dir):
|
|
|
self.dir = cast_bytes_py2(dir, sys.getdefaultencoding())
|
|
|
|
|
|
def __enter__(self):
|
|
|
if self.dir not in sys.path:
|
|
|
sys.path.append(self.dir)
|
|
|
self.added = True
|
|
|
else:
|
|
|
self.added = False
|
|
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
|
if self.added:
|
|
|
try:
|
|
|
sys.path.remove(self.dir)
|
|
|
except ValueError:
|
|
|
pass
|
|
|
# Returning False causes any exceptions to be re-raised.
|
|
|
return False
|
|
|
|
|
|
class prepended_to_syspath(object):
|
|
|
"""A context for prepending a directory to sys.path for a second."""
|
|
|
|
|
|
def __init__(self, dir):
|
|
|
self.dir = cast_bytes_py2(dir, sys.getdefaultencoding())
|
|
|
|
|
|
def __enter__(self):
|
|
|
if self.dir not in sys.path:
|
|
|
sys.path.insert(0,self.dir)
|
|
|
self.added = True
|
|
|
else:
|
|
|
self.added = False
|
|
|
|
|
|
def __exit__(self, type, value, traceback):
|
|
|
if self.added:
|
|
|
try:
|
|
|
sys.path.remove(self.dir)
|
|
|
except ValueError:
|
|
|
pass
|
|
|
# Returning False causes any exceptions to be re-raised.
|
|
|
return False
|
|
|
|
