def human_bytes(n):
    """
    Return the number of bytes n in more human readable form.
    """
    if n < 1024:
        return '%d B' % n
    k = n / 1024
    if k < 1024:
        return '%d KB' % round(k)
    m = k / 1024
    if m < 1024:
        return '%.1f MB' % m
    g = m / 1024
    return '%.2f GB' % g
