Heim  >  Artikel  >  Backend-Entwicklung  >  python使用rabbitmq实现网络爬虫示例

python使用rabbitmq实现网络爬虫示例

WBOY
WBOYOriginal
2016-06-06 11:29:061583Durchsuche

编写tasks.py

代码如下:


from celery import Celery
from tornado.httpclient import HTTPClient
app = Celery('tasks')
app.config_from_object('celeryconfig')
@app.task
def get_html(url):
    http_client = HTTPClient()
    try:
        response = http_client.fetch(url,follow_redirects=True)
        return response.body
    except httpclient.HTTPError as e:
        return None
    http_client.close()

编写celeryconfig.py

代码如下:


CELERY_IMPORTS = ('tasks',)
BROKER_URL = 'amqp://guest@localhost:5672//'
CELERY_RESULT_BACKEND = 'amqp://'

编写spider.py

代码如下:


from tasks import get_html
from queue import Queue
from bs4 import BeautifulSoup
from urllib.parse import urlparse,urljoin
import threading
class spider(object):
    def __init__(self):
        self.visited={}
        self.queue=Queue()
    def process_html(self, html):
        pass
        #print(html)
    def _add_links_to_queue(self,url_base,html):
        soup = BeautifulSoup(html)
        links=soup.find_all('a')
        for link in links:
            try:
                url=link['href']
            except:
                pass
            else:
                url_com=urlparse(url)
                if not url_com.netloc:
                    self.queue.put(urljoin(url_base,url))
                else:
                    self.queue.put(url_com.geturl())
    def start(self,url):
        self.queue.put(url)
        for i in range(20):
            t = threading.Thread(target=self._worker)
            t.daemon = True
            t.start()
        self.queue.join()
    def _worker(self):
        while 1:
            url=self.queue.get()
            if url in self.visited:
                continue
            else:
                result=get_html.delay(url)
                try:
                    html=result.get(timeout=5)
                except Exception as e:
                    print(url)
                    print(e)
                self.process_html(html)
                self._add_links_to_queue(url,html)

                self.visited[url]=True
                self.queue.task_done()
s=spider()
s.start("http://www.bitsCN.com/")

由于html中某些特殊情况的存在,程序还有待完善。

Stellungnahme:
Der Inhalt dieses Artikels wird freiwillig von Internetnutzern beigesteuert und das Urheberrecht liegt beim ursprünglichen Autor. Diese Website übernimmt keine entsprechende rechtliche Verantwortung. Wenn Sie Inhalte finden, bei denen der Verdacht eines Plagiats oder einer Rechtsverletzung besteht, wenden Sie sich bitte an admin@php.cn