How to extend a class in python?

Question

In python how can you extend a class? For example if I have

color.py

class Color:     def __init__(self, color):         self.color = color     def getcolor(self):         return self.color 

color_extended.py

import Color  class Color:     def getcolor(self):         return self.color + " extended!" 

But this doesn't work... I expect that if I work in color_extended.py, then when I make a color object and use the getcolor function then it will return the object with the string " extended!" in the end. Also it should have gotton the init from the import.

Assume python 3.1

Thanks

Answer 1

Use:

import color  class Color(color.Color):     ... 

If this were Python 2.x, you would also want to derive color.Color from object, to make it a new-style class:

class Color(object):     ... 

This is not necessary in Python 3.x.

Answer 2

class MyParent:      def sayHi():         print('Mamma says hi') 

from path.to.MyParent import MyParent  class ChildClass(MyParent):     pass 

An instance of ChildClass will then inherit the sayHi() method.