python中for循环的问题只获取最后一项

my_list = [1, 2, 3, 4, 5]
last_item = None

for item in my_list:
    last_item = item

print(last_item)  # 输出：5

my_list = [1, 2, 3, 4, 5]
last_item = my_list[-1]

print(last_item)  # 输出：5

my_list = [1, 2, 3, 4, 5]
last_item = None

for index, item in enumerate(my_list):
    if index == len(my_list) - 1:
        last_item = item

print(last_item)  # 输出：5