如何从另一个字典列表创建一个字典列表，只使用一些键：python

Question

如何将字典列表[{"a":1, "b":2, "c":3}, {"a":4, "b":5, "c":4}]转换为[{"a":1}, {"a":4}]。我编写了一个函数，只弹出循环列表中不需要的键。你知道吗

def pop_keys(dictionary, keys_to_pop):
   for item in dictionary:
        for key in keys_to_pop:
            item.pop(key, None)
   return dictionary

有没有更好最快的方法来达到同样的效果。？你知道吗

Answer 1

你可以试试

l1 = [{"a":1, "b":2, "c":3}, {"a":4, "b":5, "c":4}]
keys_to_pop = {"b", "c"} # use a set for fast lookup
l2 = [{k:v for k,v in d.items() if k not in keys_to_pop} for d in l1] # use comprehension list and dictionary