python驗證文件是否可讀可寫

# Import python libs
import os

def is_writeable(path, check_parent=False):
    '''
    Check if a given path is writeable by the current user.

:param path: The path to check
:param check_parent: If the path to check does not exist, check for the
       ability to write to the parent directory instead
:returns: True or False
'''

if os.access(path, os.F_OK) and os.access(path, os.W_OK):
    # The path exists and is writeable
    return True

if os.access(path, os.F_OK) and not os.access(path, os.W_OK):
    # The path exists and is not writeable
    return False

# The path does not exists or is not writeable

if check_parent is False:
    # We're not allowed to check the parent directory of the provided path
    return False

# Lets get the parent directory of the provided path
parent_dir = os.path.dirname(path)

if not os.access(parent_dir, os.F_OK):
    # Parent directory does not exit
    return False

# Finally, return if we're allowed to write in the parent directory of the
# provided path
return os.access(parent_dir, os.W_OK)


def is_readable(path):
    '''
    Check if a given path is readable by the current user.

:param path: The path to check
:returns: True or False
'''

if os.access(path, os.F_OK) and os.access(path, os.R_OK):
    # The path exists and is readable
    return True

# The path does not exist
return False</pre>