python - 列表操作(可变或不可变)？

Question

我有这段代码:

list1 = [1, 2, 3]
list2 = list1
list1 = [4, 5, 6]

print(list2)
print(list1)

结果如下:

[1, 2, 3]
[4, 5, 6]

为什么 list2 还没有指向 [4, 5, 6]？我的印象是，由于列表是可变的，因此更改会同时影响 list1 和 list2，因为在 RAM 中，两个列表都指向相同的项目序列。

如有任何解释，我们将不胜感激。

Answer 1

我在代码中添加了原因作为注释:

# list1 variable points to the memory location containing [1, 2, 3]
list1 = [1, 2, 3] 
# list2 variable made to point to the memory location pointed to by list1 
list2 = list1    
# list1 variable made to point to the memory location containing 
# a new list [4, 5, 6], list2 still pointing to [1, 2, 3] 
list1 = [4, 5, 6] 

print(list2) # list2 prints [1, 2, 3]
print(list1) # list1 prints [4, 5, 6]