def safe_path(path, allow_path=None):
    r'''
    .. versionadded:: 2017.7.3

    Checks that the path is safe for modification by Salt. For example, you
    wouldn't want to have salt delete the contents of ``C:\Windows``. The
    following directories are considered unsafe:

    - C:\, D:\, E:\, etc.
    - \
    - C:\Windows

    Args:

        path (str): The path to check

        allow_paths (str, list): A directory or list of directories inside of
            path that may be safe. For example: ``C:\Windows\TEMP``

    Returns:
        bool: True if safe, otherwise False
    '''
    # Create regex definitions for directories that may be unsafe to modify
    system_root = os.environ.get('SystemRoot', 'C:\\Windows')
    deny_paths = (
        r'[a-z]\:\\$',  # C:\, D:\, etc
        r'\\$',  # \
        re.escape(system_root)  # C:\Windows
    )

    # Make allow_path a list
    if allow_path and not isinstance(allow_path, list):
        allow_path = [allow_path]

    # Create regex definition for directories we may want to make exceptions for
    allow_paths = list()
    if allow_path:
        for item in allow_path:
            allow_paths.append(re.escape(item))

    # Check the path to make sure it's not one of the bad paths
    good_path = True
    for d_path in deny_paths:
        if re.match(d_path, path, flags=re.IGNORECASE) is not None:
            # Found deny path
            good_path = False

    # If local_dest is one of the bad paths, check for exceptions
    if not good_path:
        for a_path in allow_paths:
            if re.match(a_path, path, flags=re.IGNORECASE) is not None:
                # Found exception
                good_path = True

    return good_path