add Factory Method pattern

Author: JakubVojvoda

factory-method/FactoryMethod.py

@@ -0,0 +1,66 @@
+#
+# Python Design Patterns: Factory Method
+# Author: Jakub Vojvoda [github.com/JakubVojvoda]
+# 2016
+#
+# Source code is licensed under MIT License
+# (for more details see LICENSE)
+# 
+
+import sys
+
+#
+# Product
+# products implement the same interface so that the classes 
+# can refer to the interface not the concrete product
+#
+class Product:
+  def getName(self):
+    pass
+
+#
+# Concrete Products
+# define product to be created
+#
+class ConcreteProductA(Product):
+  def getName(self):
+    return "type A"
+
+class ConcreteProductB(Product):
+  def getName(self):
+    return "type B"
+
+#
+# Creator
+# contains the implementation for all of the methods
+# to manipulate products except for the factory method
+#
+class Creator:
+  def createProductA(self):
+    pass
+    
+  def createProductB(self):
+    pass
+
+#
+# Concrete Creator
+# implements factory method that is responsible for creating
+# one or more concrete products ie. it is class that has
+# the knowledge of how to create the products
+#
+class ConcreteCreator(Creator):
+  def createProductA(self):
+    return ConcreteProductA()
+  
+  def createProductB(self):
+    return ConcreteProductB()
+  
+  
+if __name__ == "__main__":
+  creator = ConcreteCreator()
+  
+  p1 = creator.createProductA()
+  print("Product: " + p1.getName())
+  
+  p2 = creator.createProductB()
+  print("Product: " + p2.getName())