python - 通过循环取消 Python 字典？

Question

我是 Python 的新手，我想要实现的是 pickle 字典，然后使用某种形式的循环(如果我的术语不正确，请见谅!)打印文件中的所有分数。

我正在使用 Python 3.3.3，这是我的尝试，用户输入一个名字和一个首先保存到文件中的分数，然后我尝试打印它。但是我无法打印分数。

import pickle

# store the scores in a pickled file
def save_scores(player, score):    

    f = open("high_score.dat", "ab")
    d = {player:score}
    pickle.dump(d, f)
    f.close

# print all the scores from the file     
def print_scores():

     # this is the part that I can't get to work!
     with open("high_score.dat", "r") as f:
        try:
            for player, score  in pickle.load(f):
                print("Player: ", player, " scored : ", score)
        except EOFError:
            pass    
    f.close

def main():

    player_name = input("Enter a name: ")
    player_score = input("Enter a score: ")

    save_scores(player = player_name, score = player_score)
    print_scores()


main()

input("\nPress the Enter key to exit")   

我用 Google 搜索过 Stackoverflow 以查找类似问题，但我一定是使用了错误的术语，因为我还没有找到解决方案。

提前致谢。

Answer 1

pickle.load(f) 将返回一个字典。如果您迭代字典，它会生成键，而不是键值对。

要生成键值对，请使用 items() 方法(如果使用 Python 2.x，请使用 iteritems() 方法):

for player, score  in pickle.load(f).items():
    print("Player: ", k, " scored : ", v)

要取出多个字典，需要循环:

with open("high_score.dat", "r") as f:
    try:
        while True:
            for player, score  in pickle.load(f).items():
                # print("Player: ", k, " scored : ", v) # k, v - typo
                print("Player: ", player, " scored : ", score)
    except EOFError:
        pass    

顺便说一句，如果你使用with语句，你不需要自己关闭文件。

# f.close # This line is not necessary. BTW, the function call is missing `()`