Python自学之乐-python 2python 3中经典类新式类的深度和广度优先小结

Posted 2020-10-07

#Author:clark
class Original(object):#在python 3 中写上object的新式类和不写的经典类遵循的都是广度优先原则
    def __init__(self):
        print("in Original")
class Second(Original):
    pass
    # def __init__(self):
    #     print("in the second")
class Third(Original):
    def __init__(self):
        print("in the third")
class  Last(Second,Third):
    pass
    # def __init__(self):
    #     print("in the last")

last_obj = Last()
运行结果为：
in the third

如果在python2中经典类结果为
in Original
新式类的结果为
in the third
可以在python2环境中试一下

总结：
python2 中经典类遵循深度优先原则，新式类遵循广度优先原则
python3 中经典类和新式类都遵循广度优先原则