Simple tornado server (web + websockets) and client for websockets.

2022/01/tornado_demo1/.gitignore

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+.idea
+*.iml
+env

2022/01/tornado_demo1/client.py

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+from tornado.ioloop import IOLoop, PeriodicCallback
+from tornado import gen
+from tornado.websocket import websocket_connect
+
+
+class Client(object):
+    def __init__(self, url, timeout):
+        self.url = url
+        self.timeout = timeout
+        self.ioloop = IOLoop.instance()
+        self.ws = None
+        self.connect()
+        PeriodicCallback(self.keep_alive, 20000).start()
+        self.ioloop.start()
+
+    @gen.coroutine
+    def connect(self):
+        print("trying to connect")
+        try:
+            self.ws = yield websocket_connect(self.url)
+            print("connected")
+            self.run()
+        except Exception:
+            print("connection error")
+
+    @gen.coroutine
+    def run(self):
+        while True:
+            msg = yield self.ws.read_message()
+            if msg is None:
+                print("connection closed")
+                self.ws = None
+                break
+            else:
+                print("Got a message: " + msg)
+
+    def keep_alive(self):
+        if self.ws is None:
+            self.connect()
+        else:
+            self.ws.write_message("keep alive")
+
+
+if __name__ == "__main__":
+    client = Client("ws://localhost:8888/socket", 5)

2022/01/tornado_demo1/requirements.txt

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+tornado

2022/01/tornado_demo1/server.py

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+import tornado.ioloop
+import tornado.web
+import tornado.websocket
+
+class MainHandler(tornado.web.RequestHandler):
+    def get(self):
+        self.write("Hello, world")
+
+class WebsocketHandler(tornado.websocket.WebSocketHandler):
+    def open(self):
+        print("Opened...")
+
+    def on_message(self, message):
+        print("Got a message: " + message)
+        self.write_message(u"You wrote: {0}".format(message))
+
+    def on_close(self):
+        print("Closed...")
+
+if __name__ == "__main__":
+    application = tornado.web.Application([
+        (r"/", MainHandler),
+        (r"/socket", WebsocketHandler),
+    ])
+    application.listen(8888)
+    tornado.ioloop.IOLoop.current().start()