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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def delete_pb_devices():
 """Delete PBs devices from the Tango database."""

    parser = argparse.ArgumentParser(description='Register PB devices.')
    parser.add_argument('num_pb', type=int,
                        help='Number of PBs devices to register.')
    args = parser.parse_args()

    log = logging.getLogger('sip.tango_control.subarray')
    tango_db = Database()
    log.info("Deleting PB devices:")
    for index in range(args.num_pb):
        name = 'sip_sdp/pb/{:05d}'.format(index)
        log.info("\t%s", name)
        tango_db.delete_device(name)