Abstract methods in Python

python inheritance abstract
user506710 picture user506710 · Dec 8, 2010 · Viewed 222.2k times · Source

I am having trouble in using inheritance with Python. While the concept seems too easy for me in Java yet up till now I have been unable to understand in Python which is surprising to me at least.

I have a prototype which follow:

class Shape():
   def __init__(self, shape_name):
       self.shape = shape_name

class Rectangle(Shape):
   def __init__(self, name):
       self.shape = name

In the above code how can I make an abstract method that would need to be implemented for all the subclasses?

Answer

kevpie picture kevpie · Dec 8, 2010

Before abc was introduced you would see this frequently.

class Base(object):
    def go(self):
        raise NotImplementedError("Please Implement this method")


class Specialized(Base):
    def go(self):
        print "Consider me implemented"

Related questions

Is it possible to make abstract classes in Python?

How can I make a class or method abstract in Python? I tried redefining __new__() like so: class F: def __new__(cls): raise Exception("Unable to create an instance of abstract class %s" %cls) but now if I create a …

Read More
Understanding Python super() with __init__() methods

I'm trying to understand the use of super(). From the looks of it, both child classes can be created, just fine. I'm curious to know about the actual difference between the following 2 child classes. class Base(object): def __init__(self): …

Read More
What are the differences between type() and isinstance()?

What are the differences between these two code fragments? Using type(): import types if type(a) is types.DictType: do_something() if type(b) in types.StringTypes: do_something_else() Using isinstance(): if isinstance(a, dict): do_something() if isinstance(…

Read More