Return the absolute path of a file or directory, specified
    as ``path`` relative to (the parent directory of) ``from_file``.

    This method is intented to be called with ``__file__``
    as second argument.

    If ``path`` is ``None``, return ``None``.

    Example: ::

        path="res/foo.bar"
        from_file="/abc/def/ghi.py"
        => "/abc/def/res/foo.bar"

    :param string path: the file path
    :param string from_file: the reference file
    :rtype: string

def absolute_path(path, from_file):
    """
    Return the absolute path of a file or directory, specified
    as ``path`` relative to (the parent directory of) ``from_file``.

    This method is intented to be called with ``__file__``
    as second argument.

    If ``path`` is ``None``, return ``None``.

    Example: ::

        path="res/foo.bar"
        from_file="/abc/def/ghi.py"
        => "/abc/def/res/foo.bar"

    :param string path: the file path
    :param string from_file: the reference file
    :rtype: string
    """
    if path is None:
        return None
    current_directory = os.path.dirname(from_file)
    target = os.path.join(current_directory, path)
    return os.path.abspath(target)