1 >>> a = [1, 2, 3]
2 >>> b = a
3 >>> id(a)
4 13081224
5 >>> id(b)
6 13081224
7 >>> a.append(4)
8 >>> b
9 [1, 2, 3, 4]

 1 >>> import copy
 2 >>> a = [1, 2, 3]
 3 >>> b = copy.deepcopy(a)  # 深拷贝
 4 >>> id(a)
 5 13098408
 6 >>> id(b)  # b和a已经不是指向同个对象
 7 12966280
 8 >>> a.append(4)
 9 >>> a
10 [1, 2, 3, 4]
11 >>> b
12 [1, 2, 3]

>>> a = [1, 2, 3]
>>> b = [4, 5, 6]
>>> c = [a, b]  # a、b均是引用
>>> c
[[1, 2, 3], [4, 5, 6]]
>>> a.append(7)
>>> c
[[1, 2, 3, 7], [4, 5, 6]]
>>>
>>> d = c
>>> id(c)
13097064
>>> id(d)
13097064
>>> e = copy.deepcopy(c)  # 深拷贝，e与其中的a、b均创建了新的内存空间
>>> id(e)
12966280
>>> a.append(8)
>>> a
[1, 2, 3, 7, 8]
>>> c
[[1, 2, 3, 7, 8], [4, 5, 6]]
>>> e
[[1, 2, 3, 7], [4, 5, 6]]
>>> f = copy.copy(c)  # 浅拷贝，对于列表f，创建了新的内存空间，但其中的a、b仅是引用
>>> id(c)
13097064
>>> id(f)
13081128
>>> a.append(9)
>>> a
[1, 2, 3, 7, 8, 9]
>>> c
[[1, 2, 3, 7, 8, 9], [4, 5, 6]]
>>> f
[[1, 2, 3, 7, 8, 9], [4, 5, 6]]

 1 >>> a = [1, 2, 3]
 2 >>> b = copy.copy(a)  # 浅拷贝可变类型，会新创建对象
 3 >>> id(a)
 4 13097480
 5 >>> id(b)
 6 13097672
 7 >>> a.append(4)
 8 >>> a
 9 [1, 2, 3, 4]
10 >>> b
11 [1, 2, 3]
12 >>>
13 >>> a = (1, 2, 3)
14 >>> b = copy.copy(a)  # 浅拷贝不可变类型，仅拷贝引用
15 >>> id(a)
16 24029512
17 >>> id(b)
18 24029512

1 >>> a = "abc"
2 >>> b = a[:]  # 仅拷贝引用
3 >>> id(a)
4 23728480
5 >>> id(b)
6 23728480

1 >>> a = {1: 2, 2: "a"}
2 >>> b = a.copy()  # 会创建新对象
3 >>> id(a)
4 23759080
5 >>> id(b)
6 23759040

 1 >>> a = [1, 2]
 2 >>> b = list(a)  # 不可变类型，创建新对象
 3 >>> id(a)
 4 13097672
 5 >>> id(b)
 6 13213224
 7 >>> a = dict(a=1, b=2)
 8 >>> b = dict(a)  # 不可变类型，创建新对象
 9 >>> id(a)
10 13107104
11 >>> id(b)
12 13106464
13 >>> a = (1, 2)
14 >>> b = tuple(a)  # 可变类型，仅拷贝引用
15 >>> id(a)
16 13159912
17 >>> id(b)
18 13159912