add Proxy pattern

Author: JakubVojvoda

proxy/Proxy.py

@@ -0,0 +1,48 @@
+#
+# Python Design Patterns: Proxy
+# Author: Jakub Vojvoda [github.com/JakubVojvoda]
+# 2016
+#
+# Source code is licensed under MIT License
+# (for more details see LICENSE)
+# 
+
+import sys
+
+#
+# Subject
+# defines the common interface for RealSubject and Proxy
+# so that a Proxy can be used anywhere a RealSubject is expected
+#
+class Subject:
+  def request(self):
+    pass
+
+#
+# Real Subject
+# defines the real object that the proxy represents
+#
+class RealSubject(Subject):
+  def __init__(self):
+    Subject.__init__(self)  
+    
+  def request(self):
+    print("Real Subject request.")
+
+#
+# Proxy
+# maintains a reference that lets the proxy access the real subject
+#
+class Proxy(Subject):
+  def __init__(self):
+    Subject.__init__(self)
+    self._subject = RealSubject()
+    
+  def request(self):
+    self._subject.request()
+
+
+if __name__ == "__main__":
+  proxy = Proxy()
+  proxy.request()
+