Python - 使用 HTTPS 的 urllib2 异步/线程请求示例

Question

我很难使用 Python 的 urllib2 来获取异步/线程 HTTPS 请求。

有没有人有一个实现 urllib2.Request、urllib2.build_opener 和 urllib2.HTTPSHandler 子类的基本示例？

谢谢！

Answer 1

下面的代码同时异步执行 7 个 http 请求。
它不使用线程，而是使用 twisted 库的异步网络。

from twisted.web import client
from twisted.internet import reactor, defer

urls = [
 'http://www.python.org', 
 'http://stackoverflow.com', 
 'http://www.twistedmatrix.com', 
 'http://www.google.com',
 'http://launchpad.net',
 'http://github.com',
 'http://bitbucket.org',
]

def finish(results):
    for result in results:
        print 'GOT PAGE', len(result), 'bytes'
    reactor.stop()

waiting = [client.getPage(url) for url in urls]
defer.gatherResults(waiting).addCallback(finish)

reactor.run()

Answer 2

有一个非常简单的方法，涉及 urllib2 的处理程序，您可以在这里找到它： http: //pythonquirks.blogspot.co.uk/2009/12/asynchronous-http-request.html

#!/usr/bin/env python

import urllib2
import threading

class MyHandler(urllib2.HTTPHandler):
    def http_response(self, req, response):
        print "url: %s" % (response.geturl(),)
        print "info: %s" % (response.info(),)
        for l in response:
            print l
        return response

o = urllib2.build_opener(MyHandler())
t = threading.Thread(target=o.open, args=('http://www.google.com/',))
t.start()
print "I'm asynchronous!"

t.join()

print "I've ended!"

Answer 3

这是使用 urllib2 （带有 https）和线程的示例。每个线程循环访问 URL 列表并检索资源。

import itertools
import urllib2
from threading import Thread


THREADS = 2
URLS = (
    'https://foo/bar',
    'https://foo/baz',
    )


def main():
    for _ in range(THREADS):
        t = Agent(URLS)
        t.start()


class Agent(Thread):
    def __init__(self, urls):
        Thread.__init__(self)
        self.urls = urls

    def run(self):
        urls = itertools.cycle(self.urls)
        while True:
            data = urllib2.urlopen(urls.next()).read()


if __name__ == '__main__':
    main()

Answer 4

您可以使用异步 IO 来执行此操作。

请求 + gevent = grequests

GRequests 允许您使用带有 Gevent 的请求来异步HTTP轻松提出要求。

import grequests

urls = [
    'http://www.heroku.com',
    'http://tablib.org',
    'http://httpbin.org',
    'http://python-requests.org',
    'http://kennethreitz.com'
]

rs = (grequests.get(u) for u in urls)
grequests.map(rs)

Answer 5

这是来自 eventlet 的代码

urls = ["http://www.google.com/intl/en_ALL/images/logo.gif",
     "https://wiki.secondlife.com/w/images/secondlife.jpg",
     "http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif"]

import eventlet
from eventlet.green import urllib2

def fetch(url):

  return urllib2.urlopen(url).read()

pool = eventlet.GreenPool()

for body in pool.imap(fetch, urls):
  print "got body", len(body)