<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def process_items(r, keys, timeout, limit=0, log_every=1000, wait=.1):
 """Process items from a redis queue. Parameters r : Redis Redis connection instance. keys : list List of keys to read the items from. timeout: int Read timeout. """

    limit = limit or float('inf')
    processed = 0
    while processed < limit:
        # Change ``blpop`` to ``brpop`` to process as LIFO.
        ret = r.blpop(keys, timeout)
        # If data is found before the timeout then we consider we are done.
        if ret is None:
            time.sleep(wait)
            continue

        source, data = ret
        try:
            item = json.loads(data)
        except Exception:
            logger.exception("Failed to load item:\n%r", pprint.pformat(data))
            continue

        try:
            name = item.get('name') or item.get('title')
            url = item.get('url') or item.get('link')
            logger.debug("[%s] Processing item: %s <%s>", source, name, url)
        except KeyError:
            logger.exception("[%s] Failed to process item:\n%r",
                             source, pprint.pformat(item))
            continue

        processed += 1
        if processed % log_every == 0:
            logger.info("Processed %s items", processed)