如果列表中的项目a在列表中b

Question

我有两个清单.我需要编写一个函数detect,其

a'for item in list_a'循环以检查item_b中是否存在该项.

我该怎么做呢？没有合适的关键字我找不到任何东西!

list_a = ["Q", "W", "E"]
list_b = ["Q", "D", "E"]

def detect(item):
    return

detect(list_a[0])  
>>True
detect(list_a[1])
>>False

我试过了:

for item in list_a:
    if item in list_b:
        return True
    else:
        return False

Answer 1

>>> set_b = set(["Q", "D", "E"])
>>> set_a = set(["Q", "W", "E"])
>>> set_a.intersection(set_b)
set(['Q', 'E'])
>>> 'Q' in set_a.intersection(set_b)
True
>>> '42' in set_a.intersection(set_b)
False