比如字典：

my_dict = {"first_key": 'first_value',"second_key": "second_value","third_key": "third_value",}

如果使用：

print(my_dict.keys()[0])print(my_dict.values()[0])

这会导致报错：

TypeError: 'dict_keys' object is not subscriptableTypeError: 'dict_values' object is not subscriptable

选取第一个元素

my_dict = {"first_key": 'first_value',"second_key": "second_value","third_key": "third_value",}print("first key : ", next(iter(my_dict)))print("first value : ", my_dict.get(next(iter(my_dict))))

选取最后一个元素

print("last key : ", list(my_dict.keys())[-1])print("last value : ", my_dict.get(list(my_dict.keys())[-1]))