Comparable python chat implementation

chat-threads.py

@@ -0,0 +1,49 @@
+from __future__ import with_statement
+from SocketServer import ThreadingMixIn, TCPServer, StreamRequestHandler
+from threading import RLock
+
+active_connections = set()
+active_connection_mutex = RLock()
+
+class ChatServer(ThreadingMixIn, TCPServer):
+    allow_reuse_address = True
+
+counter = 0
+
+class ConnectionHandler(StreamRequestHandler):
+    def handle(self):
+        global counter
+        self.connection_id = 'user' + str(counter)
+        counter = counter + 1
+        try:
+            self.arrive()
+            while True:
+                line = self.rfile.readline()
+                if not line: break
+                for c in active_connections.copy():
+                    c.announce('%s says %s' % (self.connection_id, line.strip()))
+        finally:
+            self.depart()
+
+    def arrive(self):
+        self.announce('you are %s' % (self.connection_id,))
+        with active_connection_mutex:
+            for c in active_connections:
+                c.announce('%s arrived' % (self.connection_id,))
+            active_connections.add(self)
+
+    def depart(self):
+        with active_connection_mutex:
+            active_connections.discard(self)
+            for c in active_connections:
+                c.announce('%s departed' % (self.connection_id,))
+
+    def announce(self, s):
+        try:
+            self.wfile.write(s + '\n')
+        except IOError:
+            self.depart()
+
+if __name__ == '__main__':
+    s = ChatServer(('localhost', 5999), ConnectionHandler)
+    s.serve_forever()