Laurence Tratt notes that the accept() call in get_request() can fail,

and suggests putting a try/except around the get_request() call in
handle_request().  (All in class TCPServer.)

Lib/SocketServer.py

@@ -207,7 +207,10 @@ def serve_forever(self):
 
     def handle_request(self):
         """Handle one request, possibly blocking."""
+        try:
             request, client_address = self.get_request()
+        except socket.error:
+            return
         if self.verify_request(request, client_address):
             try:
                 self.process_request(request, client_address)