Python 如何从嵌套字典中查找公共键值对

发布于03月24日

我有一本嵌套字典:

Movies = {1: {'1060277': 'cloverfield', '1877830': 'The Batman', '0117283': 'The Pallbearer'},
          2: {'1877830': 'The Batman', '1877321': 'The Yards', '0117283': 'The Pallbearer'},
          3: {'6723592': 'Tenet', '1099212': 'Twilight', '1877830': 'The Batman'}}

现在，我想返回一个字典，它包含嵌套字典中所有字典的公共键值对，在本例中是

--> 1877830 The Batman

因为它是所有3个嵌套字典中唯一通用的一个.

我似乎搞不懂如何比较这些字典:

#mov is where Movies will be passed    
def Narrow_down(mov):
      final_list= mov[1]
      for i in final_list.keys():
        for x,y in mov.items(): 
            for key in y:
                if i==key:
                    print(i, "is common ")

推荐答案

基本上，你需要第一本字典，然后对于每一本下一本字典，只保留第一本字典中的键，这些键也在下一本字典中.

一个非常简单的解决方案使用functools.reduce():

from functools import reduce

# you don't really need the outer dictionary, but if you do, this is list(Movies.values())
movies = [
    {'1060277': 'cloverfield', '1877830': 'The Batman', '0117283': 'The Pallbearer'},
    {'1877830': 'The Batman', '1877321': 'The Yards', '0117283': 'The Pallbearer'},
    {'6723592': 'Tenet', '1099212': 'Twilight', '1877830': 'The Batman'}
]

result = reduce(lambda d1, d2: {k: v for k, v in d1.items() if k in d2 and d2[k] == d1[k]}, movies)

print(result)

结果: