def _cat_log(fs, path):
    """fs.cat() the given log, converting lines to strings, and logging
    errors."""
    try:
        if not fs.exists(path):
            return
        for line in fs.cat(path):
            yield to_string(line)
    except IOError as e:
        log.warning((path, e) % "couldn't cat() %s: %r")
dataset/ETHPy150Open Yelp/mrjob/mrjob/logs/wrap.py/_cat_log/swapped operands of `%`