def bytes_fmt(value):
    """Format a byte value human readable.

    Args:
        value (float): value of bytes
    Returns:
        str: formated value with unit
    """
    for unit in ['', 'K', 'M', 'G']:
        if abs(value) < 1024.0:
            return '{:3.2}f{}B'.format(value, unit)
        value /= 1024.0
    return '{:3.2}fTB'.format(value, 'G')