def human_bytes(n):
    """
    return the number of bytes 'n' in more human readable form
    """
    if n < 1024:
        return '%i B' % n
    k = (n - 1) / 1024 + 1
    if k < 1024:
        return '%i KB' % k
    return '%.2f MB' % (float(n) / 2 ** 20)
