Compare by iteration

def compare(dicts):
    """Compare by iteration"""

    common_members = {}
    common_keys = reduce(lambda x, y: x & y, map(dict.keys, dicts))
    for k in common_keys:
        common_members[k] = list(
            reduce(lambda x, y: x & y, [set(d[k]) for d in dicts]))

    return common_members