in
判断单个元素是否在序列中， 对字典来说只能判断key
print("ab" in "abcdefg")
print("abc" in ["abc", "ac"])
print([1, 2] in [[1, 2], "3"])
print("abc" in {"abc": 33})
print(33 in {"abc": 33})
is
身份判断，判断内存地址是否相等
nameOne = "BeiMenChuiXue" nameTwo = "QiNiuYun" nameThree = "QiNiuYun" print(nameOne is nameTwo, id(nameOne), id(nameTwo)) print(nameTwo is nameThree, id(nameTwo), id(nameThree))
==
判断值是否相等
nameOne = "BeiMenChuiXue" nameTwo = "QiNiuYun" nameThree = "QiNiuYun" print(nameOne == nameTwo) print(nameTwo == nameThree)
相同点
in is == 返回都是bool类型
原文：https://www.cnblogs.com/2bjiujiu/p/9085918.html