<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def _walk_through(job_dir):
    '''
    Walk though the jid dir and look for jobs
    '''
    serial = salt.payload.Serial(__opts__)

    for top in os.listdir(job_dir):
        t_path = os.path.join(job_dir, top)

        if not os.path.exists(t_path):
            continue

        for final in os.listdir(t_path):
            load_path = os.path.join(t_path, final, LOAD_P)

            if not os.path.isfile(load_path):
                continue

            with salt.utils.files.fopen(load_path, 'rb') as rfh:
                try:
                    job = serial.load(rfh)
                except Exception:
                    log.exception('Failed to deserialize %s', load_path)
                    continue
                if not job:
                    log.error('Deserialization of job succeded but there is no data in %s', load_path)
                    continue
                jid = job['jid']
                yield jid, job, t_path, final