Abstraction in Python?

Question

I am a little bit unclear about how to use abstraction and classes. I have abstract classes for a graph and a graph advanced, that looks something like this

class AbstractGraph: 

   def method1(self): 

      raise NotImplementedError

   ...

class AbstractAdvanced:

   def method2(self):

      raise NotImplementedError 

   ... 

I then have an implementation of a graph:

class Graph(AbstractGraph):

   def method1(self):

      * actual code * 

Now my main problem is: can I do something like this?

class Advanced(AbstractAdvanced, AbstractGraph):

   def method2(self):

      *actual code, using the methods from AbstractGraph*

Answer 1

Please be informed that you can create abstract base classes, however, they are of confined utility. It's more common to start your class hierarchy with particular classes.

#Always inherit from object, or some subtype thereof, unless you want your code to behave differently in python 2 and python 3

class AbstractGraph(object): 

   def method1(self): 

      raise NotImplementedError

class Graph(AbstractGraph):

   def method1(self):

      * actual code * 

class GraphToo(AbstractGraph):

   def method1(self):

      * actual code * 

class AbstractAdvanced(AbstractGraph):

   def method2(self):

      raise NotImplementedError 

class Advanced(Graph,AbstractAdvanced):

   def method2(self):

      *actual code, using the methods from Graph*

# order of classes in the inheritance list matters - it will affect the method resolution order

class AdvancedToo(GraphToo, Advanced): pass

Kindly refer to the Python tutorial for more information regrading classes and objects.