如何使用python实现垂直爬虫系统
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小编给大家分享一下如何使用python实现垂直爬虫系统，希望大家阅读完这篇文章之后都有所收获，下面让我们一起去探讨吧！
html_downloader
from urllib import requestdef download(url): if url is None: return response = request.urlopen(url) if response.getcode() != 200: return None return response.read()html_outeputer
data_list = []def collect_data(data): data_list.append(data)def output_html(): fout = open('output.html', 'w') fout.write('<html>') fout.write('<body>') fout.write('<table>') for dataitem in data_list: fout.write('<tr>') fout.write('<td>%s</td>' % dataitem['url']) fout.write('<td>%s</td>' % dataitem['title']) fout.write('<td>%s</td>' % dataitem['datetime']) fout.write('<td>%s</td>' % dataitem['visitcount']) fout.write('</tr>') fout.write('</table>') fout.write('</body>') fout.write('</html>') fout.close()html_parser
import refrom bs4 import BeautifulSoupfrom urllib.parse import urljoindef get_new_urls(page_url, soup): new_urls = set() links = soup.find_all('a', href=re.compile(r"/\d+/\d+/\w+/page\.htm")) for link in links: new_url = link['href'] new_full_url = urljoin(page_url, new_url) new_urls.add(new_full_url) return new_urlsdef get_new_data(page_url, soup): res_data = {} title_node = soup.find('h2', class_='arti-title') if title_node is None: return res_data res_data['title'] = title_node.get_text() datetime_node = soup.find('span', class_='arti-update') res_data['datetime'] = datetime_node.get_text() visitcount_node = soup.find('span', class_='WP_VisitCount') res_data['visitcount'] = visitcount_node.get_text() res_data['url'] = page_url return res_datadef parse(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 = get_new_urls(page_url, soup) new_data = get_new_data(page_url, soup) return new_urls, new_dataspider_main
import urls_manager, html_downloader, \ html_parser, html_outputerdef craw(root_url): count = 1 urls_manager.add_new_url(root_url) #启动爬虫循环 while urls_manager.has_new_url(): new_url = urls_manager.get_new_url() print('craw %d : %s' % (count, new_url)) html_cont = html_downloader.download(new_url) new_urls, new_data = html_parser.parse(new_url, html_cont) urls_manager.add_new_urls(new_urls) if new_data: html_outputer.collect_data(new_data) if count == 10: break count = count + 1 html_outputer.output_html()if __name__ == '__main__': root_url = 'http://news.zzuli.edu.cn/' craw(root_url)import urls_manager, html_downloader, \ html_parser, html_outputerdef craw(root_url): count = 1 urls_manager.add_new_url(root_url) #启动爬虫循环 while urls_manager.has_new_url(): new_url = urls_manager.get_new_url() print('craw %d : %s' % (count, new_url)) html_cont = html_downloader.download(new_url) new_urls, new_data = html_parser.parse(new_url, html_cont) urls_manager.add_new_urls(new_urls) if new_data: html_outputer.collect_data(new_data) if count == 10: break count = count + 1 html_outputer.output_html()if __name__ == '__main__': root_url = 'http://news.zzuli.edu.cn/' craw(root_url)test_64
from bs4 import BeautifulSoupimport rehtml_doc = """<html><head><title>The Dormouse's story</title></head><body><p class="title"><b>The Dormouse's story</b></p><p class="story">Once upon a time there were three little sisters; and their names were<a href="http://example.com/elsie" class="sister" id="link1">Elsie</a>,<a href="http://example.com/lacie" class="sister" id="link2">Lacie</a> and<a href="http://example.com/tillie" class="sister" id="link3">Tillie</a>;and they lived at the bottom of a well.</p><p class="story">...</p>"""soup = BeautifulSoup(html_doc, 'html.parser')print('获取所有链接')links = soup.find_all('a')for link in links: print(link.name, link['href'], link.get_text())print('获取lacie链接')link_node = soup.find('a', href='http://example.com/lacie')print(link_node.name, link_node['href'], link_node.get_text())print('正则匹配')link_node = soup.find('a', href=re.compile(r'ill'))print(link_node.name, link_node['href'], link_node.get_text())print('获取P段落文字')p_node = soup.find('p', class_='title')print(p_node.name, p_node.get_text())urls_manager
new_urls = set()old_urls = set()def add_new_url(url): if url is None: return if url not in new_urls and url not in old_urls: new_urls.add(url)def add_new_urls(urls): if urls is None or len(urls) == 0: return for url in urls: add_new_url(url)def get_new_url(): new_url = new_urls.pop() old_urls.add(new_url) return new_urldef has_new_url(): return len(new_urls) != 0看完了这篇文章，相信你对“如何使用python实现垂直爬虫系统”有了一定的了解，如果想了解更多相关知识，欢迎关注编程网行业资讯频道，感谢各位的阅读！
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