Wanted functionality from Counters (new in Python 2.7).

def most_common(items):
    """
    Wanted functionality from Counters (new in Python 2.7).
    """
    counts = {}
    for i in items:
        counts.setdefault(i, 0)
        counts[i] += 1
    return max(six.iteritems(counts), key=operator.itemgetter(1))