from http.server import BaseHTTPRequestHandler, HTTPServer

class RequestHandler(BaseHTTPRequestHandler):
    
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type','text/html')
        self.end_headers()
        message = "Hello world!"
        self.wfile.write(bytes(message, "utf8"))
        return

addr = ('127.0.0.1', 8080)
HTTPServer(addr, RequestHandler).serve_forever()