python中的is判断引用的对象是否一致,==判断值是否相等
a = 10 b = 20 list = [1,2,3,4,5] print(a in list) print(b not in list) a = 20 print(a in list) print(a is b) print('*'*20) c = 'c' d = 'c' print(c is d) # True 这个是个变量缓存的概念 c = 'c'*10000 d = 'c'*10000 print(c is d) # False 字符串太长就不一致的 print(c==d) # True 这个值就是相等的了