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最近在學習Python,自然接觸到了爬蟲,寫了一個小型爬蟲軟件,從初始Url解析網頁,使用正則獲取待爬取鏈接,使用beautifulsoup解析獲取文本,使用自己寫的輸出器可以將文本輸出保存,具體代碼如下:
Spider_main.py
# 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(): print("self.urls.has %s" % self.urls.new_urls) 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 failed") self.outputer.output_html() self.outputer.output_txt() if __name__ == '__main__': root_url = "http://www.shushu8.com/jiangnan/longzu2qianzhuan/1" obj_spider = SpiderMain() obj_spider.craw(root_url)
url_manager.py
class UrlManager(object): def __init__(self): self.new_urls = set() self.old_urls = set() def add_new_url(self, url): print(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) # print('new url is %s' % new_url) return new_url def add_new_urls(self, urls): print("add_new_urls %s" % urls) if urls is None or len(urls) == 0: return for url in urls: self.add_new_url(url) print(url)
html_parser.py
import re import urllib.parse from bs4 import BeautifulSoup class HtmlParser(object): 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) print("parse new_urls %s" % new_urls) new_data = self._get_new_data(page_url, soup) return new_urls, new_data def _get_new_data(self, page_url, soup): res_data = {} res_data['url'] = page_url print(page_url) title_node = soup.find(class_="title").find("h2") print(title_node.get_text()) res_data['title'] = title_node.get_text() print("_get_new_data") summary_node = soup.find('pre') print(summary_node.get_text()) res_data['summary'] = summary_node.get_text() return res_data def _get_new_urls(self, page_url, soup): new_urls = set() links = soup.find_all('a', href=re.compile(r"/jiangnan/")) print(links) for link in links: new_url = link['href'] new_full_url = urllib.parse.urljoin(page_url, new_url) new_urls.add(new_full_url) # print(new_full_url) return new_urls
html_downloader.py
import urllib.request class HtmlDownloader(object): def download(self, url): if url is None: return None response = urllib.request.urlopen(url) if response.getcode() != 200: return None return response.read()
html_outputer.py
class HtmlOutputer(object): def __init__(self): self.datas = [] def collect_data(self, data): if data is None: return self.datas.append(data) def output_txt(self): fout = open('output.txt', 'w', encoding='utf-8') for data in self.datas: fout.write('%s \n' % data['title']) fout.write('%s \n' % data['summary']) def output_html(self): fout = open('output.html', 'w', encoding='utf-8') 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']) fout.write('<td>%s</td>' % data['summary']) fout.write('</tr>') fout.write('</table>') fout.write('</body>') fout.write('</html>') fout.close()
總結
以上所述是小編給大家介紹的Python實現爬蟲從網絡上下載文檔的實例代碼,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對億速云網站的支持!
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