python - 在python中反转字典

Question

我有这本字典

{'jackie chan': ('rush hour', 'rush hour 2'), 
 'crish tucker': ('rush hour', 'rush    hour 2')}

我希望逆字典是

{'rush hour': ('jackie chan', 'crish tucker'), 
 'rush hour 2': ('jackie chan', 'crish tucker')}

我已经得到了反转的功能，但它看起来不像第二个字典

def invert_actor_dict(actor_dict):
    movie_dict = {}
    for key,value in actor_dict.iteritems():

        for actor in value:
            if actor in movie_dict:
                movie_dict[actor].append(key)
            else:
                movie_dict[actor] = (key)
    return movie_dict

Answer 1

您可以使用 collections.defaultdict 轻松完成此操作:

def invert_dict(d):
    inverted_dict = collections.defaultdict(set)
    for actor, movies in d.iteritems():
        for movie in movies:
            inverted_dict.add(actor)
    return inverted_dict