Retrieve how long ago a file has been accessed.

    :param filename: name of the file

    >>> print accessed(__file__)        # doctest: +SKIP
    just now

def accessed(filename):
    '''
    Retrieve how long ago a file has been accessed.

    :param filename: name of the file

    >>> print accessed(__file__)        # doctest: +SKIP
    just now
    '''
    if isinstance(filename, file):
        filename = filename.name

    return duration(os.stat(filename)[stat.ST_ATIME])