def human_filesize(number):
    """
    Human readable file size unit
    :param number: how many bytes
    :return: (num, unit)
    """
    units = ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']
    for unit in units:
        if number < 10000 or unit == 'YB':
            return number, unit
        else:
            number = number / 1024.0
