1、打开电脑运行，输入‘cmd’进入命令行窗口，输入‘python’
2、定义a列表，通过工厂模式浅拷贝b列表,代码如下：
>>> a=[1,2,[1,2]]
>>> b=list(a)
>>> [x for x in a]
[1, 2, [1, 2]]
>>> [x for x in b]
[1, 2, [1, 2]]
>>> [id(x) for x in a]
[1575119888, 1575119920, 38676616]
>>> [id(x) for x in b]
[1575119888, 1575119920, 38676616]
>>>
3、通过赋值或切片方式：
>>> c = a 或 c=a[:]或c=[i for i in a]
>>> [id(x) for x in a]
[1575119888, 1575119920, 38676616]
>>> [id(x) for x in c]
[1575119888, 1575119920, 38676616]
>>>
4、通过copy函数，代码如下：
>>> import copy
>>> d = copy.copy(a)
>>> [id(x) for x in a]
[1575119888, 1575119920, 38676616]
>>> [id(x) for x in d]
[1575119888, 1575119920, 38676616]
>>>
5、以上就是三种浅拷贝的方法，增加一个嵌套列表中的元素，会影响两个。
>>> a[2].append(3)
>>> a
[1, 2, [1, 2, 3]]
>>> b
[1, 2, [1, 2, 3]]
>>>
6、改变外层列表只影响自己，代码如下：
>>> a.append(4)
>>> a
[1, 2, [1, 2, 3], 4]
>>> b
[1, 2, [1, 2, 3]]
>>>
