Python多线程、异步+多进程爬虫实现代码

安装Tornado
省事点可以直接用grequests库,下面用的是tornado的异步client。 异步用到了tornado,根据官方文档的例子修改得到一个简单的异步爬虫类。可以参考下最新的文档学习下。
pip install tornado

异步爬虫

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
 
import time
from datetime import timedelta
from tornado import httpclient, gen, ioloop, queues
import traceback
 
 
class AsySpider( object ):
   """A simple class of asynchronous spider."""
   def __init__( self , urls, concurrency = 10 , * * kwargs):
     urls.reverse()
     self .urls = urls
     self .concurrency = concurrency
     self ._q = queues.Queue()
     self ._fetching = set ()
     self ._fetched = set ()
 
   def fetch( self , url, * * kwargs):
     fetch = getattr (httpclient.AsyncHTTPClient(), 'fetch' )
     return fetch(url, * * kwargs)
 
   def handle_html( self , url, html):
     """handle html page"""
     print (url)
 
   def handle_response( self , url, response):
     """inherit and rewrite this method"""
     if response.code = = 200 :
       self .handle_html(url, response.body)
 
     elif response.code = = 599 # retry
       self ._fetching.remove(url)
       self ._q.put(url)
 
   @gen .coroutine
   def get_page( self , url):
     try :
       response = yield self .fetch(url)
       print ( '######fetched %s' % url)
     except Exception as e:
       print ( 'Exception: %s %s' % (e, url))
       raise gen.Return(e)
     raise gen.Return(response)
 
   @gen .coroutine
   def _run( self ):
     @gen .coroutine
     def fetch_url():
       current_url = yield self ._q.get()
       try :
         if current_url in self ._fetching:
           return
 
         print ( 'fetching****** %s' % current_url)
         self ._fetching.add(current_url)
 
         response = yield self .get_page(current_url)
         self .handle_response(current_url, response)  # handle reponse
 
         self ._fetched.add(current_url)
 
         for i in range ( self .concurrency):
           if self .urls:
             yield self ._q.put( self .urls.pop())
 
       finally :
         self ._q.task_done()
 
     @gen .coroutine
     def worker():
       while True :
         yield fetch_url()
 
     self ._q.put( self .urls.pop())  # add first url
 
     # Start workers, then wait for the work queue to be empty.
     for _ in range ( self .concurrency):
       worker()
 
     yield self ._q.join(timeout = timedelta(seconds = 300000 ))
     assert self ._fetching = = self ._fetched
 
   def run( self ):
     io_loop = ioloop.IOLoop.current()
     io_loop.run_sync( self ._run)
 
 
class MySpider(AsySpider):
 
   def fetch( self , url, * * kwargs):
     """重写父类fetch方法可以添加cookies,headers,timeout等信息"""
     cookies_str = "PHPSESSID=j1tt66a829idnms56ppb70jri4; pspt=%7B%22id%22%3A%2233153%22%2C%22pswd%22%3A%228835d2c1351d221b4ab016fbf9e8253f%22%2C%22_code%22%3A%22f779dcd011f4e2581c716d1e1b945861%22%7D; key=%E9%87%8D%E5%BA%86%E5%95%84%E6%9C%A8%E9%B8%9F%E7%BD%91%E7%BB%9C%E7%A7%91%E6%8A%80%E6%9C%89%E9%99%90%E5%85%AC%E5%8F%B8; think_language=zh-cn; SERVERID=a66d7d08fa1c8b2e37dbdc6ffff82d9e|1444973193|1444967835; CNZZDATA1254842228=1433864393-1442810831-%7C1444972138"  # 从浏览器拷贝cookie字符串
     headers = {
       'User-Agent' : 'mozilla/5.0 (compatible; baiduspider/2.0; +http://www.baidu.com/search/spider.html)' ,
       'cookie' : cookies_str
     }
     return super (MySpider, self ).fetch(  # 参数参考tornado文档
       url, headers = headers, request_timeout = 1
     )
 
   def handle_html( self , url, html):
     print (url, html)
 
 
def main():
   urls = []
   for page in range ( 1 , 100 ):
     urls.append( 'http://www.baidu.com?page=%s' % page)
   s = MySpider(urls)
   s.run()
 
 
if __name__ = = '__main__' :
   main()

可以继承这个类,塞一些url进去,然后重写handle_page处理得到的页面。

异步+多进程爬虫
还可以再变态点,加个进程池,使用了multiprocessing模块。效率飕飕的,

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
 
import time
from multiprocessing import Pool
from datetime import timedelta
from tornado import httpclient, gen, ioloop, queues
 
 
class AsySpider( object ):
   """A simple class of asynchronous spider."""
   def __init__( self , urls, concurrency):
     urls.reverse()
     self .urls = urls
     self .concurrency = concurrency
     self ._q = queues.Queue()
     self ._fetching = set ()
     self ._fetched = set ()
 
   def handle_page( self , url, html):
     filename = url.rsplit( '/' , 1 )[ 1 ]
     with open (filename, 'w+' ) as f:
       f.write(html)
 
   @gen .coroutine
   def get_page( self , url):
     try :
       response = yield httpclient.AsyncHTTPClient().fetch(url)
       print ( '######fetched %s' % url)
     except Exception as e:
       print ( 'Exception: %s %s' % (e, url))
       raise gen.Return('')
     raise gen.Return(response.body)
 
   @gen .coroutine
   def _run( self ):
 
     @gen .coroutine
     def fetch_url():
       current_url = yield self ._q.get()
       try :
         if current_url in self ._fetching:
           return
 
         print ( 'fetching****** %s' % current_url)
         self ._fetching.add(current_url)
         html = yield self .get_page(current_url)
         self ._fetched.add(current_url)
 
         self .handle_page(current_url, html)
 
         for i in range ( self .concurrency):
           if self .urls:
             yield self ._q.put( self .urls.pop())
 
       finally :
         self ._q.task_done()
 
     @gen .coroutine
     def worker():
       while True :
         yield fetch_url()
 
     self ._q.put( self .urls.pop())
 
     # Start workers, then wait for the work queue to be empty.
     for _ in range ( self .concurrency):
       worker()
     yield self ._q.join(timeout = timedelta(seconds = 300000 ))
     assert self ._fetching = = self ._fetched
 
   def run( self ):
     io_loop = ioloop.IOLoop.current()
     io_loop.run_sync( self ._run)
 
 
def run_spider(beg, end):
   urls = []
   for page in range (beg, end):
     urls.append( 'http://127.0.0.1/%s.htm' % page)
   s = AsySpider(urls, 10 )
   s.run()
 
 
def main():
   _st = time.time()
   p = Pool()
   all_num = 73000
   num = 4  # number of cpu cores
   per_num, left = divmod (all_num, num)
   s = range ( 0 , all_num, per_num)
   res = []
   for i in range ( len (s) - 1 ):
     res.append((s[i], s[i + 1 ]))
   res.append((s[ len (s) - 1 ], all_num))
   print res
 
   for i in res:
     p.apply_async(run_spider, args = (i[ 0 ], i[ 1 ],))
   p.close()
   p.join()
 
   print time.time() - _st
 
 
if __name__ = = '__main__' :
   main()

多线程爬虫
线程池实现.

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#!/usr/bin/env python
# -*- coding:utf-8 -*-
import Queue
import sys
import requests
import os
import threading
import time
 
class Worker(threading.Thread):  # 处理工作请求
   def __init__( self , workQueue, resultQueue, * * kwds):
     threading.Thread.__init__( self , * * kwds)
     self .setDaemon( True )
     self .workQueue = workQueue
     self .resultQueue = resultQueue
 
 
   def run( self ):
     while 1 :
       try :
         callable , args, kwds = self .workQueue.get( False # get task
         res = callable ( * args, * * kwds)
         self .resultQueue.put(res)  # put result
       except Queue.Empty:
         break
 
class WorkManager:  # 线程池管理,创建
   def __init__( self , num_of_workers = 10 ):
     self .workQueue = Queue.Queue()  # 请求队列
     self .resultQueue = Queue.Queue()  # 输出结果的队列
     self .workers = []
     self ._recruitThreads(num_of_workers)
 
   def _recruitThreads( self , num_of_workers):
     for i in range (num_of_workers):
       worker = Worker( self .workQueue, self .resultQueue)  # 创建工作线程
       self .workers.append(worker)  # 加入到线程队列
 
 
   def start( self ):
     for w in self .workers:
       w.start()
 
   def wait_for_complete( self ):
     while len ( self .workers):
       worker = self .workers.pop()  # 从池中取出一个线程处理请求
       worker.join()
       if worker.isAlive() and not self .workQueue.empty():
         self .workers.append(worker)  # 重新加入线程池中
     print 'All jobs were complete.'
 
 
   def add_job( self , callable , * args, * * kwds):
     self .workQueue.put(( callable , args, kwds))  # 向工作队列中加入请求
 
   def get_result( self , * args, * * kwds):
     return self .resultQueue.get( * args, * * kwds)
 
 
def download_file(url):
   #print 'beg download', url
   requests.get(url).text
 
 
def main():
   try :
     num_of_threads = int (sys.argv[ 1 ])
   except :
     num_of_threads = 10
   _st = time.time()
   wm = WorkManager(num_of_threads)
   print num_of_threads
   urls = [ 'http://www.baidu.com' ] * 1000
   for i in urls:
     wm.add_job(download_file, i)
   wm.start()
   wm.wait_for_complete()
   print time.time() - _st
 
if __name__ = = '__main__' :
   main()

这三种随便一种都有很高的效率,但是这么跑会给网站服务器不小的压力,尤其是小站点,还是有点节操为好。

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