[Python] Tornado Example

tornado_async_example.py

import tornado.web
from tornado.ioloop import IOLoop
from tornado import gen

from tornado.concurrent import run_on_executor
from concurrent.futures import ThreadPoolExecutor

MAX_WORKERS = 16

class TestHandler(tornado.web.RequestHandler):
    executor = ThreadPoolExecutor(max_workers=MAX_WORKERS)

    """
    In below function goes your time consuming task
    """
    @run_on_executor
    def background_task(self):
        sm = 0
        for i in range(10 ** 8):
            sm = sm + 1
        return sm

    @gen.coroutine
    def get(self):
        """ Request that asynchronously calls background task. """
        res = yield self.background_task()
        self.write(str(res))

class TestHandler2(tornado.web.RequestHandler):

    @gen.coroutine
    def get(self):
        self.write('Response from server')
        self.finish()

application = tornado.web.Application([
    (r"/A", TestHandler),
    (r"/B", TestHandler2),
    ])

application.listen(5000)
IOLoop.instance().start()