Python asyncio

sample0.py

import time
import random


URIS = ("http://example.org/foo", "http://example.org/bar",
        "http://example.org/baz")


def main():
    for uri in URIS:
        res = fetch(uri)
        print("---- %s (%s)" % (res, uri))


def fetch(uri):
    print("GET %s" % uri)
    response = _http()
    print("%s kB" % response)
    return response


def _http():
    time.sleep(1.0)
    return random.randint(0, 9)


main()

sample1.py

import asyncio
import random


URIS = ("http://example.org/foo", "http://example.org/bar",
        "http://example.org/baz")


@asyncio.coroutine
def main():
    for uri in URIS:
        res = yield from fetch(uri)
        print("---- %s (%s)" % (res, uri))


@asyncio.coroutine
def fetch(uri):
    print("GET %s" % uri)
    response = yield from _http()
    print("%s kB" % response)
    return response


@asyncio.coroutine
def _http():
    yield from asyncio.sleep(1.0)
    return random.randint(0, 9)


loop = asyncio.get_event_loop()
loop.run_until_complete(main())
loop.close()

sample2.py

import asyncio
import random


URIS = ("http://example.org/foo", "http://example.org/bar",
        "http://example.org/baz")


def main():
    for uri in URIS:
        task = asyncio.Task(fetch(uri))
        print("---- registered %s" % task)


@asyncio.coroutine
def fetch(uri):
    print("retrieving %s..." % uri)
    response = yield from _http()
    print("downloaded %s kB" % response)
    return response


@asyncio.coroutine
def _http():
    yield from asyncio.sleep(1.0)
    return random.randint(0, 9)


main()
loop = asyncio.get_event_loop()
try:
    loop.run_forever()
finally:
    loop.close()

sample3.py

import asyncio
import random


URIS = ("http://example.org/foo", "http://example.org/bar",
        "http://example.org/baz")


def main(loop):
    req_count = 0

    def shutdown():
        if req_count == len(URIS):
            loop.stop()

    for uri in URIS:
        task = asyncio.Task(fetch(uri))
        task.add_done_callback(lambda task: shutdown())
        req_count += 1
        print("---- registered #%s %s" % (req_count, task))


@asyncio.coroutine
def fetch(uri):
    print("retrieving %s..." % uri)
    response = yield from _http()
    print("downloaded %s kB" % response)
    return response


@asyncio.coroutine
def _http():
    yield from asyncio.sleep(1.0)
    return random.randint(0, 9)


loop = asyncio.get_event_loop()
main(loop)
try:
    loop.run_forever()
finally:
    loop.close()