def format_bytes(bytes):
    """Helper to convert bytes into respective formats.
    
    :param bytes(byte)  : Bytes to formate
    :return (byte)      : formatted bytes
    """

    if abs(bytes) < 1000:
        return str(bytes) + 'B'
    elif abs(bytes) < 1e6:
        return str(round(bytes / 1e3, 2)) + 'kB'
    elif abs(bytes) < 1e9:
        return str(round(bytes / 1e6, 2)) + 'MB'
    else:
        return str(round(bytes / 1e9, 2)) + 'GB'