sdk/platform-tools/systrace/catapult/telemetry/third_party/pyfakefs/pyfakefs/example.py

   1 # Copyright 2014 Altera Corporation. All Rights Reserved.
   2 # Author: John McGehee
   3 #
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7 #
   8 #      http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 """
  17 Example module that is tested in :py:class`pyfakefs.example_test.TestExample`.
  18 This demonstrates the usage of the
  19 :py:class`pyfakefs.fake_filesystem_unittest.TestCase` base class.
  20
  21 The modules related to file handling are bound to the respective fake modules:
  22
  23 >>> os     #doctest: +ELLIPSIS
  24 <fake_filesystem.FakeOsModule object...>
  25 >>> os.path     #doctest: +ELLIPSIS
  26 <fake_filesystem.FakePathModule object...>
  27 >>> glob     #doctest: +ELLIPSIS
  28 <fake_filesystem_glob.FakeGlobModule object...>
  29 >>> shutil     #doctest: +ELLIPSIS
  30 <fake_filesystem_shutil.FakeShutilModule object...>
  31
  32 The `open()` built-in is bound to the fake `open()`:
  33
  34 >>> open     #doctest: +ELLIPSIS
  35 <fake_filesystem.FakeFileOpen object...>
  36
  37 In Python 2 the `file()` built-in is also bound to the fake `open()`.  `file()`
  38 was eliminated in Python 3.
  39 """
  40
  41 import os
  42 import glob
  43 import shutil
  44
  45 def create_file(path):
  46     '''Create the specified file and add some content to it.  Use the `open()`
  47     built in function.
  48
  49     For example, the following file operations occur in the fake file system.
  50     In the real file system, we would not even have permission to write `/test`:
  51
  52     >>> os.path.isdir('/test')
  53     False
  54     >>> os.mkdir('/test')
  55     >>> os.path.isdir('/test')
  56     True
  57     >>> os.path.exists('/test/file.txt')
  58     False
  59     >>> create_file('/test/file.txt')
  60     >>> os.path.exists('/test/file.txt')
  61     True
  62     >>> with open('/test/file.txt') as f:
  63     ...     f.readlines()
  64     ["This is test file '/test/file.txt'.\\n", 'It was created using the open() function.\\n']
  65     '''
  66     with open(path, 'w') as f:
  67         f.write("This is test file '{}'.\n".format(path))
  68         f.write("It was created using the open() function.\n")
  69
  70 def delete_file(path):
  71     '''Delete the specified file.
  72
  73     For example:
  74
  75     >>> os.mkdir('/test')
  76     >>> os.path.exists('/test/file.txt')
  77     False
  78     >>> create_file('/test/file.txt')
  79     >>> os.path.exists('/test/file.txt')
  80     True
  81     >>> delete_file('/test/file.txt')
  82     >>> os.path.exists('/test/file.txt')
  83     False
  84     '''
  85     os.remove(path)
  86
  87 def path_exists(path):
  88     '''Return True if the specified file exists.
  89
  90     For example:
  91
  92     >>> path_exists('/test')
  93     False
  94     >>> os.mkdir('/test')
  95     >>> path_exists('/test')
  96     True
  97     >>>
  98     >>> path_exists('/test/file.txt')
  99     False
 100     >>> create_file('/test/file.txt')
 101     >>> path_exists('/test/file.txt')
 102     True
 103     '''
 104     return os.path.exists(path)
 105
 106 def get_glob(glob_path):
 107     '''Return the list of paths matching the specified glob expression.
 108
 109     For example:
 110
 111     >>> os.mkdir('/test')
 112     >>> create_file('/test/file1.txt')
 113     >>> create_file('/test/file2.txt')
 114     >>> get_glob('/test/file*.txt')
 115     ['/test/file1.txt', '/test/file2.txt']
 116     '''
 117     return glob.glob(glob_path)
 118
 119 def rm_tree(path):
 120     '''Delete the specified file hierarchy.'''
 121     shutil.rmtree(path)