add Bridge pattern

Author: JakubVojvoda

bridge/Bridge.py

@@ -0,0 +1,49 @@
+#
+# Python Design Patterns: Bridge
+# Author: Jakub Vojvoda [github.com/JakubVojvoda]
+# 2016
+#
+# Source code is licensed under MIT License
+# (for more details see LICENSE)
+# 
+
+import sys
+
+#
+# Implementor
+# defines the interface for implementation classes
+#
+class Implementor:
+  def action(self):
+    pass
+
+#
+# Concrete Implementors
+# implement the Implementor interface and define concrete implementations
+#
+class ConcreteImplementorA(Implementor):
+  def action(self):
+    print("Concrete Implementor A")
+
+class ConcreteImplementorB(Implementor):
+  def action(self):
+    print("Concrete Implementor B")
+
+#
+# Bridge
+# decouple an abstraction from its implementation
+#
+class Bridge:
+  def __init__(self, implementation):
+    self._implementor = implementation
+  
+  def operation(self):
+    self._implementor.action()
+
+
+if __name__ == "__main__":
+  bridge = Bridge(ConcreteImplementorA())
+  bridge.operation()
+  
+  bridge = Bridge(ConcreteImplementorB())
+  bridge.operation()