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参考python官方文档copy — 浅层 (shallow) 和深层 (deep) 复制操作，收藏一下。
浅层与深层复制的区别仅与复合对象（即包含列表或类的实例等其他对象的对象）相关：
浅层复制 构造一个新的复合对象，然后（在尽可能的范围内）将原始对象中找到的对象的 引用 插入其中。
深层复制 构造一个新的复合对象，然后，递归地将在原始对象里找到的对象的 副本 插入其中。
代码测试
一些代码测试
以列表为例，若直接b = a，则相当于引用，对b操作等同于对a操作。
浅拷贝：
b = a[:]或b = copy.copy(a)
深拷贝：
b = copy.deepcopy(a)
浅拷贝
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = a[:]
print(b)
b[0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[‘abc’, [3, 4]]
[[1, 2], [3, 4]]
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = a[:]
print(b)
b[0][0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[[‘abc’, 2], [3, 4]]
[[‘abc’, 2], [3, 4]]
import copy
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = copy.copy(a)
print(b)
b[0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[‘abc’, [3, 4]]
[[1, 2], [3, 4]]
import copy
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = copy.copy(a)
print(b)
b[0][0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[[‘abc’, 2], [3, 4]]
[[‘abc’, 2], [3, 4]]
可见在列表中b = a[:]与b = copy.copy(a)效果一致。
深拷贝
import copy
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = copy.deepcopy(a)
print(b)
b[0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[‘abc’, [3, 4]]
[[1, 2], [3, 4]]
import copy
x = [1, 2]
y = [3, 4]
a = [x, y]
print(a)
b = copy.deepcopy(a)
print(b)
b[0][0] = 'abc'
print(b)
print(a)
[[1, 2], [3, 4]]
[[1, 2], [3, 4]]
[[‘abc’, 2], [3, 4]]
[[1, 2], [3, 4]]
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