Micropython (ESP8266) websocket server implementation.
Upload all scripts and HTML page to device and execute the websocket_demo.py script.
When client connects to the device, test.html is served to him, which in turn makes websocket connection to the device and greets it with Hello. The device acknowledges this and replies with World appended, which makes client display Hello World.
New implementations can be made by subclassing WebSocketClient and WebSocketServer as shown in websocket_demo.py.
Because setsockopt can't be used on ESP32 to install event handlers, new implementation using Poll class has been made and is available in separate folder. From user perspective, both implementation behave the same.
Also, if you're having problems importing websocket class, make sure that it's available in your firmware using following commands. websocket class should be listed in the output.
import websocket # This is importing module, not class
dir(websocket) # List everything that module supports
Micropython revision 0d5bccad is confirmed to be working correctly. Thanks for this goes to @plugowski.