aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/python/ipython/py2/IPython/utils/syspathcontext.py
blob: fdcfbbee358e0cc0f842aacf380867cee926981c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
# 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