第一行：craw 1 : None。第二行：craw field
主代码:
# coding:utf8 #encoding=utf-8** 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) html_cont = self.downloader.download() new_urls, new_data = self.parser.parse(new_url, html_cont) self.urls.add_new_urls(new_urls) self.outputer.collect_data(new_data) if count == 1000: print 'done' break count = count + 1 except: print 'craw field' self.outputer.output_html() if __name__ == "__main__": root_url = "https://baike.baidu.com/item/Python/407313?fr=aladdin" obj_spider = SpiderMain() obj_spider.craw(root_url)
管理器：
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, new_urls): if urls is 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
解析器：
class HtmlParser(object):
def _get_new_urls(self, page_url, soup):
new_urls = set()
# /view/123.htm
links = soup.find_all('a', herf=re.compile(r"/item/\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
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"
summary_node = soup.find('div', class_ ="lemma-summary")
res_data['summary'] = sumary_node.get_text()
return res_data
def parse(self, pew_url, html_cont):
if page_url is None or html_cont is None:
return
soup = BeautifulSoup(html_cont,'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_data输出器：
class Htmloutputer(object):
def __init__(self):
self.datas = []
def collect_data(self, new_data):
if data is None:
return
self.datas.append(data)
def output_html(self):
fout = open('output.html', 'w')
fout.write("<html>")
fout.write("<body>")
fout.write("<table>")
for data in self.datas:
fout.write("<tr>")
fout.write("<rd>%s</td>" % data['url'])
fout.write("<rd>%s</td>" % data['title'].encode('uft-8'))
fout.write("<rd>%s</td>" % data['summary'].encode('uft-8'))
fout.write("</tr>")
fout.write("</table>")
fout.write("<body>")
fout.write("<html>")下载器：
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()
输出结果：
craw 1 : None
craw field
Process finished with exit code 0
