def compare ( dicts ) : 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
python iterate through two dictionary keys and create a list of common values as strings
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