Added explanation about the Factory Method pattern.

Author: mshcruz

creational/factory_method.py

@@ -1,7 +1,33 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-"""http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/"""
+"""
+*What is this pattern about?
+The Factory Method pattern can be used to create an interface for a
+method, leaving the implementation to the class that gets
+instantiated.
+
+*What does this example do?
+The code shows a way to localize words in two languages: English and
+Greek. "getLocalizer" is the factory method that constructs a
+localizer depending on the language chosen. The localizer object will
+instantiate a different class according to the language of that
+localized, but the main code does not have to worry about which
+localizer will be instantiated, since the method "get" will be called
+in the same way independently of the language.
+
+*Where can the pattern be used practically?
+The Factory Method can be seen in the popular web framework Django:
+http://django.wikispaces.asu.edu/*NEW*+Django+Design+Patterns 
+For example, in a contact form, the subject and the message fields are
+created using the same form factory (CharField()), even though they
+will have different implementations according to their purposes.
+
+*References:
+http://ginstrom.com/scribbles/2007/10/08/design-patterns-python-style/
+https://fkromer.github.io/python-pattern-references/design/#factory-method
+https://sourcemaking.com/design_patterns/factory_method
+"""
 
 
 class GreekGetter(object):