Python拷贝分为深拷贝和浅拷贝

• 浅拷贝对子对象不拷贝，深拷贝全部拷贝

l1 = [1, 2, [3, 4]]
l2 = copy.copy(l1)
l1.append(5)
l1[2].append(5)  # 子对象 改变
print(l1)
print(l2)
--------------
[1, 2, [3, 4, 5], 5]
[1, 2, [3, 4, 5]]

• 深拷贝完是两个完全不相干的对象

l1 = [1, 2, [3, 4]]
l2 = copy.deepcopy(l1)
l1.append(5)
l1[2].append(5)
print(l1)
print(l2)
--------------
[1, 2, [3, 4, 5], 5]
[1, 2, [3, 4]]