Tornado + yield from = <3

Output

# http://localhost:8888/?mode=sync

http://wikipedia.com code: 200
http://google.com code: 200
http://example.com code: 200

#> time curl http://localhost:8888/\?mode\=sync
http://wikipedia.com code: 200<br/>http://google.com code: 200<br/>http://example.com code: 200curl http://localhost:8888/\?mode\=sync  0,01s user 0,00s system 0% cpu 1,106 total

# http://localhost:8888/?mode=async

http://wikipedia.com code: 200
http://google.com code: 200
http://example.com code: 200

#> time curl http://localhost:8888/\?mode\=async
http://wikipedia.com code: 200<br/>http://google.com code: 200<br/>http://example.com code: 200curl http://localhost:8888/\?mode\=async  0,00s user 0,00s system 2% cpu 0,402 total

tornado_yield_from.py

from tornado.ioloop import IOLoop
from tornado.gen import coroutine
from tornado.httpclient import AsyncHTTPClient, HTTPClient
import tornado.web

from inspect import isgeneratorfunction

class MainHandler(tornado.web.RequestHandler):

    @coroutine
    def get(self):
        urls = ['http://wikipedia.com', 'http://google.com', 'http://example.com']

        modes = {'sync': self._get_sync, 'async': self._get_async}
        mode = self.get_argument('mode', 'sync')

        method = modes[mode]

        if isgeneratorfunction(method):
            result = yield from method(urls)
        else:
            result = method(urls)

        self.write('<br/>'.join(result))

    def _get_async(self, urls):
        body = []
        results = yield from self._async(urls)
        return ('%s code: %s' % (response.request.url, response.code) for response in results)

    def _get_sync(self, urls):
        body = []
        for url in urls:
            result = self._sync(url)
            body.append('%s code: %s' % (url, result.code))
        return body

    def _sync(self, url):
        http_client = HTTPClient()
        return http_client.fetch(url)

    def _async(self, urls):
        http_client = AsyncHTTPClient()
        result = yield [http_client.fetch(url) for url in urls]
        return result

application = tornado.web.Application([
    (r"/", MainHandler),
])

if __name__ == "__main__":
    application.listen(8888)
    tornado.ioloop.IOLoop.instance().start()