python实现多线程网页下载器

Python  /  管理员 发布于 7年前   164

本文为大家分享了python实现的一个多线程网页下载器，供大家参考，具体内容如下

这是一个有着真实需求的实现，我的用途是拿它来通过 HTTP 方式向服务器提交游戏数据。把它放上来也是想大家帮忙挑刺，找找 bug，让它工作得更好。

keywords:python,http,multi-threads,thread,threading,httplib,urllib,urllib2,Queue,http pool,httppool

废话少说，上源码：

# -*- coding:utf-8 -*- import urllib, httplib import thread import time from Queue import Queue, Empty, Full HEADERS = {"Content-type": "application/x-www-form-urlencoded", 'Accept-Language':'zh-cn', 'User-Agent': 'Mozilla/4.0 (compatible; MSIE 6.0;Windows NT 5.0)', "Accept": "text/plain"} UNEXPECTED_ERROR = -1 POST = 'POST' GET = 'GET' def base_log(msg):   print msg def base_fail_op(task, status, log):   log('fail op. task = %s, status = %d'%(str(task), status)) def get_remote_data(tasks, results, fail_op = base_fail_op, log = base_log):   while True:     task = tasks.get()     try:       tid = task['id']       hpt = task['conn_args'] # hpt <= host:port, timeout     except KeyError, e:       log(str(e))       continue     log('thread_%s doing task %d'%(thread.get_ident(), tid))     #log('hpt = ' + str(hpt))     conn = httplib.HTTPConnection(**hpt)try:       params = task['params']     except KeyError, e:       params = {}     params = urllib.urlencode(params)     #log('params = ' + params)          try:       method = task['method']     except KeyError:       method = 'GET'     #log('method = ' + method)          try:       url = task['url']     except KeyError:       url = '/'     #log('url = ' + url)          headers = HEADERS     try:       tmp = task['headers']     except KeyError, e:       tmp = {}     headers.update(tmp)     #log('headers = ' + str(headers))     headers['Content-Length'] = len(params)          try:       if method == POST:         conn.request(method, url, params, headers)       else:         conn.request(method, url + params)       response = conn.getresponse()     except Exception, e:       log('request failed. method = %s, url = %s, params = %s headers = %s'%( method, url, params, headers))       log(str(e))       fail_op(task, UNEXPECTED_ERROR, log)       continueif response.status != httplib.OK:       fail_op(task, response.status, log)       continuedata = response.read()     results.put((tid, data), True)      class HttpPool(object):   def __init__(self, threads_count, fail_op, log):     self._tasks = Queue()     self._results = Queue()          for i in xrange(threads_count):       thread.start_new_thread(get_remote_data,        (self._tasks, self._results, fail_op, log))          def add_task(self, tid, host, url, params, headers = {}, method = 'GET', timeout = None):     task = {       'id' : tid,       'conn_args' : {'host' : host} if timeout is None else {'host' : host, 'timeout' : timeout},       'headers' : headers,       'url' : url,       'params' : params,       'method' : method,       }     try:       self._tasks.put_nowait(task)     except Full:       return False     return True        def get_results(self):     results = []     while True:       try:         res = self._results.get_nowait()       except Empty:         break       results.append(res)     return results      def test_google(task_count, threads_count):   hp = HttpPool(threads_count, base_fail_op, base_log)   for i in xrange(task_count):     if hp.add_task(i,         'www.google.cn',         '/search?',         {'q' : 'lai'}, #        method = 'POST'         ):       print 'add task successed.'          while True:     results = hp.get_results()     if not results:       time.sleep(1.0 * random.random())     for i in results:       print i[0], len(i[1]) #      print unicode(i[1], 'gb18030')        if __name__ == '__main__':   import sys, random   task_count, threads_count = int(sys.argv[1]), int(sys.argv[2])   test_google(task_count, threads_count)

 有兴趣想尝试运行的朋友，可以把它保存为 xxxx.py，然后执行 python xxxx.py 10 4，其中 10 表示向 google.cn 请求 10 次查询，4 表示由 4 条线程来执行这些任务。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。