def human_size(size, units=(' bytes', ' KB', ' MB', ' GB', ' TB', ' PB', ' EB')):
    """
    Returns a human readable string representation of bytes
    """
    return "{}".rjust(6 - len(str(size))).format(str(size)) + units[0] if size < 1024 else human_size(size >> 10, units[1:])