Python爬取百度百科页面数据

Python爬取百度百科页面数据我将他分为五部分：主函数部分、URL管理器部分、网页下载器部分、网页解析器部分和输出部分，以下是代码：

主函数部分spider_main.py

# coding=UTF-8
'''
Created on 2017年4月4日
@author: zwl
'''
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)
                html_cont = self.downloader.download(new_url)
                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: 
                    break
                    
                count = count + 1
            except:
                print 'craw faild'    
        self.outputer.output_html()    




if __name__=="__main__":
    root_url = "http://baike.baidu.com/item/Python?sefr=cr"
    obj_spider = SpiderMain()
    obj_spider.craw(root_url)
    
    

URL管理器部分url_manager.py
   # coding=UTF-8
'''
Created on 2017年4月4日


@author: zwl
'''


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 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


    
    def add_new_urls(self, urls):
        if urls is None or len(urls) == 0:
            return
        for url in urls:
            self.add_new_url(url)
    

网页下载器部分html_downloader.py
   # coding=UTF-8
'''
Created on 2017年4月4日


@author: zwl
'''
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()
    
    网页解析器部分html_parser.py

# coding=UTF-8
'''
Created on 2017年4月4日

@author: zwl
'''
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(r"/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 = {}
        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()
        
    
    def parse(self, page_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
    

输出部分html_outputer.py

# coding=UTF-8
'''
Created on 2017年4月4日


@author: zwl
'''




class HtmlOutputer(object):
    def __init__(self):
        self.datas = []
    
    def collect_data(self, 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("<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()