2019-01-02答:list1 = [1, 10, 220, 12, 9, 0] # 5//2 length = len(list1) if length % 2 == 0: print(list1[length//2 -1], list1[length//2]) else: print(list1[length//2]) list1 = [1, 10, 220, 12, 9, 0] print(sum(list1)) """ isinstance(数据, 类型) --> 判断指定的数据...