1.創建baike_spider包
2.創建調度模塊：
#coding:utf8
from baike_spider import url_manager, html_downloader, html_parser,\
html_outputer
class SpiderMain(object):
def __init__(self):
self.urls = url_manager.UrlManager()
self.downloader = html_downloader.HtmlDownloader()
self.parser = html_parser.HtmlParser()
self.outputer = html_outputer.HtmlOutputer()
def craw(self,root_url):
count = 1
self.urls.add_new_url(root_url)
while self.urls.has_new_url():
try:
new_url = self.urls.get_new_url()
print 'craw %d : %s' % (count,new_url)
new_cont = self.downloader.download(new_url)
new_urls,new_data = self.parser.parse(new_url,new_cont)
self.urls.add_new_urls(new_urls)
self.outputer.collect_data(new_data)
if count == 100:
break
count = count + 1
except:
print 'craw failed'
self.outputer.out_html()
if __name__=="__main__":
root_url = "http://baike.baidu.com/link?url=Ak2ZeZ5dQxpl3iq7SFtqYNsp6L-QSKgg7tWodHFgJ0lViVE59bpDoX054BZza0R-vgS6gih9QygDM0GMLbz97_"
obj_spider = SpiderMain()
obj_spider.craw(root_url)
print "finish!!!!"3.創建url管理器模塊：
#coding:utf8
class UrlManager(object):
def __init__(self):
self.new_urls = set()
self.old_urls = set()
def add_new_url(self,url):
if url is None:
return
if url not in self.new_urls and url not in self.old_urls:
self.new_urls.add(url)
def add_new_urls(self,urls):
if urls == None or len(urls)==0:
return;
for url in urls:
self.add_new_url(url)
def has_new_url(self):
return len(self.new_urls) != 0
def get_new_url(self):
new_url = self.new_urls.pop()
self.old_urls.add(new_url)
return new_url#coding:utf8
import urllib2
class HtmlDownloader(object):
def download(self,url):
if url is None:
return None
response = urllib2.urlopen(url)
if response.getcode()!=200:
return None
return response.read()5.創建url解析器模塊：
#coding:utf8
from bs4 import BeautifulSoup
import re
import urlparse
class HtmlParser(object):
def _get_new_urls(self, page_url, soup):
new_urls = set()
links = soup.find_all('a',href = re.compile('/view/\d+\.htm'))
for link in links:
new_url = link['href']
new_full_url = urlparse.urljoin(page_url, new_url)
new_urls.add(new_full_url)
return new_urls
def _get_new_data(self, page_url, soup):
res_data = {}
#url
res_data['url'] = page_url
#<dd class="lemmaWgt-lemmaTitle-title"><h1>Python</h1>
title_node = soup.find('dd',class_ = "lemmaWgt-lemmaTitle-title").find("h1")
res_data['title'] = title_node.get_text()
#<div class="lemma-summary" label-module="lemmaSummary">
summary_node = soup.find('div',class_ = "lemma-summary")
res_data['summary'] = summary_node.get_text()
return res_data
def parse(self,page_url,html_data):
if page_url is None or html_data is None:
return
soup = BeautifulSoup(html_data,'html.parser',from_encoding = 'utf-8')
new_urls = self._get_new_urls(page_url,soup)
new_data = self._get_new_data(page_url,soup)
return new_urls,new_data6.創建url打印輸出模塊：
#coding:utf8
class HtmlOutputer(object):
def __init__(self):
self.datas = []
def collect_data(self,data):
if data is None:
return
self.datas.append(data)
def out_html(self):
fout = open('output.html','w')
fout.write("<html>")
fout.write(r'<head><meta charset="utf-8"></head>')
fout.write("<body>")
fout.write("<table>")
for data in self.datas:
fout.write("<tr>")
fout.write("<td>%s</td>"%data['url'])
fout.write("<td>%s</td>"%data['title'].encode('utf-8'))
fout.write("<td>%s</td>"%data['summary'].encode('utf-8'))
fout.write("</tr>")
fout.write("</table>")
fout.write("</body>")
fout.write("</html>")
fout.close()