25页：recommend()函数少了一行代码

[yunque0]

    movies = dict()
    for (sim_user,sim) in newNU[:self.k]:
        for movieID in self.train[sim_user].keys():
            movies.setdefault(movieID,0)  #书中少了这句代码
            movies[movieID] += sim * self.train[sim_user][movieID]
    newMovies = sorted(movies.items(), key = lambda  k:k[1], reverse=True)
    return newMovies

[Thinkgamer]

源码包中有，书中缺失