python ＝赋值、copy、deep copy

import copya = [1,2,3,4]b = a               # 赋值时，　把列表的引用传给ｂprint(id(a))print(id(b))print(a)print(b)b = copy.copy(a)   # 对于可变类型变量，　浅拷贝会将引用和内容全部拷贝一份传给ｂ，即递归所有　a.append(5)print(id(a))print(id(b))print(a)print(b)a = (1,2,3,4)  b = aprint(id(a))print(id(b))print(a)print(b)b = copy.copy(a)    # 对于不可变类型变量，　浅拷贝只将引用传给新变量print(id(a))print(id(b))print(a)print(b)

运行结果：

140718278173768140718278173768[1, 2, 3, 4][1, 2, 3, 4]140718278173768140718278192264[1, 2, 3, 4, 5][1, 2, 3, 4]140718302072248140718302072248(1, 2, 3, 4)(1, 2, 3, 4)140718302072248140718302072248(1, 2, 3, 4)(1, 2, 3, 4)