我該如何優化時間這個Python代碼

Question

我寫這段代碼，但我覺得它非常慢，我不知道如何真正改善它的時間。 data是一個約有70 000個鍵的json對象。我認爲最慢的部分是actors部分，因爲我在列表中迭代（最多包含3個元素）。

genres_number = {} 
actors_number = {}  
for movie in data: 
    for genre in data[movie]["genres"]: 
     if data[movie]["actors"] != None: 
      for actor in data[movie]["actors"]: 
       if actor not in actors_number.keys(): 
        actors_number[actor] = 1 
       else: 
        actors_number[actor] = actors_number[actor] + 1 
     if genre not in genres_number.keys(): 
      genres_number[genre] = 1 
     else: 
      genres_number[genre] = genres_number[genre] + 1 
res = [] 
res.append(genres_number) 
res.append(actors_number) 
return res 

Answer 1

這是如何對你的工作

from collections import defaultdict 

def get_stats(data): 
    genres_number = defaultdict(int) 
    actors_number = defaultdict(int) 

    for movie in data: 

     actors = movie.get('actors') 
     if actors: 
      for actor in actors: 
       actors_number[actor] += 1 

     genres = movie.get('genres') 
     for genre in genres: 
      genres_number[actor] += 1 

    res = [] 
    res.append(dict(genres_number)) 
    res.append(dict(actors_number)) 
    return res