python super用法 2018-01-28

新式类，经典类

python3之后均称为新式类，默认继承object类

Python2.x版本分为：分新式类与经典类

新式类：每个类都继承于一个基类，可以是自定义类或者其它类，默认承于object

旧式类：不继承object类

mro算法：方法解析顺序

新式类中采用广度算法，经典类中采用深度算法

super 仅用于新式类

super 用法

In Python 3 and above, the syntax for super is:

super().methoName(args)

Whereas the normal way to call super (in older builds of Python) is:

super(subClass, instance).method(args)

单个继承初始化

class MyParentClass(object):def __init__(self):pass

class SubClass(MyParentClass):def __init__(self):MyParentClass.__init__(self)

If we were using Python 2, we would write the subclass like this (using the super function):

class SubClass(MyParentClass):

def __init__(self):

super(SubClass, self).__init__()

The same code is slightly different when writing in Python 3, however.

class MyParentClass():def __init__(self):pass

class SubClass(MyParentClass):def __init__(self):

    super()

Now, keep in mind most classes will also have arguments passed to them. The super function will change even more when that happens.

It will look like the following:

class MyParentClass():def __init__(self, x, y):pass

class SubClass(MyParentClass):def __init__(self, x, y):super().__init__(x, y)

In Python 3 and above, the syntax for super is:

super().methoName(args)

Whereas the normal way to call super (in older builds of Python) is:

super(subClass, instance).method(args)

新式类中mro：广度搜索

super的原理：遍历当前类的mro列表，查找含有当前方法的第一个类，找到则用类调用方法，退出

Demo