如何扩展 Python 类 init

How to extend Python class init

提问by MFB

I have created a base class:

我创建了一个基类：

class Thing():
    def __init__(self, name):
        self.name = name

I want to extend the class and add to the initmethod so the that SubThinghas both a nameand a timeproperty. How do I do it?

我想扩展该类并添加到init方法中，以便SubThing同时具有 aname和 atime属性。我该怎么做？

class SubThing(Thing):
    # something here to extend the init and add a "time" property

    def __repr__(self):
        return '<%s %s>' % (self.name, self.time)

Any help would be awesome.

任何帮助都是极好的。

采纳答案by Jesse

You can just define __init__in the subclass and call superto call the parents' __init__methods appropriately:

您可以__init__在子类中定义并调用super以__init__适当地调用父类的方法：

class SubThing(Thing):
    def __init__(self, *args, **kwargs):
        super(SubThing, self).__init__(*args, **kwargs)
        self.time = datetime.now()

Make sure to have your base class subclass from objectthough, as superwon't work with old-style classes:

确保有你的基类子类object，因为super不适用于旧式类：

class Thing(object):
    ...

回答by mariosangiorgio

You should write another __init__method in SubThingand then call the constructor of the superclass to initialize its fields.

您应该在其中编写另一个__init__方法SubThing，然后调用超类的构造函数来初始化其字段。

This Q&A should provide you some more examples.

此问答应该为您提供更多示例。