catapult/telemetry/third_party/pyfakefs/pyfakefs/example.py

# Copyright 2014 Altera Corporation. All Rights Reserved.
# Author: John McGehee
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Example module that is tested in :py:class`pyfakefs.example_test.TestExample`.
This demonstrates the usage of the
:py:class`pyfakefs.fake_filesystem_unittest.TestCase` base class.

The modules related to file handling are bound to the respective fake modules:

>>> os     #doctest: +ELLIPSIS 
<fake_filesystem.FakeOsModule object...>
>>> os.path     #doctest: +ELLIPSIS
<fake_filesystem.FakePathModule object...>
>>> glob     #doctest: +ELLIPSIS
<fake_filesystem_glob.FakeGlobModule object...>
>>> shutil     #doctest: +ELLIPSIS
<fake_filesystem_shutil.FakeShutilModule object...>

The `open()` built-in is bound to the fake `open()`:

>>> open     #doctest: +ELLIPSIS
<fake_filesystem.FakeFileOpen object...>

In Python 2 the `file()` built-in is also bound to the fake `open()`.  `file()`
was eliminated in Python 3.
"""

import os
import glob
import shutil

def create_file(path):
    '''Create the specified file and add some content to it.  Use the `open()`
    built in function.
    
    For example, the following file operations occur in the fake file system.
    In the real file system, we would not even have permission to write `/test`:
    
    >>> os.path.isdir('/test')
    False
    >>> os.mkdir('/test')
    >>> os.path.isdir('/test')
    True
    >>> os.path.exists('/test/file.txt')
    False
    >>> create_file('/test/file.txt')
    >>> os.path.exists('/test/file.txt')
    True
    >>> with open('/test/file.txt') as f:
    ...     f.readlines()
    ["This is test file '/test/file.txt'.\\n", 'It was created using the open() function.\\n']
    '''
    with open(path, 'w') as f:
        f.write("This is test file '{}'.\n".format(path))
        f.write("It was created using the open() function.\n")

def delete_file(path):
    '''Delete the specified file.
    
    For example:
        
    >>> os.mkdir('/test')
    >>> os.path.exists('/test/file.txt')
    False
    >>> create_file('/test/file.txt')
    >>> os.path.exists('/test/file.txt')
    True
    >>> delete_file('/test/file.txt')
    >>> os.path.exists('/test/file.txt')
    False
    '''
    os.remove(path)
    
def path_exists(path):
    '''Return True if the specified file exists.
    
    For example:
        
    >>> path_exists('/test')
    False
    >>> os.mkdir('/test')
    >>> path_exists('/test')
    True
    >>>
    >>> path_exists('/test/file.txt')
    False
    >>> create_file('/test/file.txt')
    >>> path_exists('/test/file.txt')
    True
    '''
    return os.path.exists(path)

def get_glob(glob_path):
    '''Return the list of paths matching the specified glob expression.
    
    For example:
    
    >>> os.mkdir('/test')
    >>> create_file('/test/file1.txt')
    >>> create_file('/test/file2.txt')
    >>> get_glob('/test/file*.txt')
    ['/test/file1.txt', '/test/file2.txt']
    '''
    return glob.glob(glob_path)

def rm_tree(path):
    '''Delete the specified file hierarchy.'''
    shutil.rmtree(path)