from crawler_test.html_downloader import UrlDownLoader from crawler_test.html_outer import HtmlOuter from crawler_test.html_parser import HtmlParser from crawler_test.url_manager import UrlManager # 爬虫主程序入口 class MainCrawler(): def __init__(self): # 初始值，实例化四大处理器：url管理器，下载器，解析器，输出器 self.urls = UrlManager() self.downloader = UrlDownLoader() self.parser = HtmlParser() self.outer = HtmlOuter() # 开始爬虫方法 def start_craw(self, main_url): print('爬虫开始...') count = 1 self.urls.add_new_url(main_url) while self.urls.has_new_url(): try: new_url = self.urls.get_new_url() print('爬虫%d,%s' % (count, new_url)) html_cont = self.downloader.down_load(new_url) new_urls, new_data = self.parser.parse(new_url, html_cont) # 将解析出的url放入url管理器，解析出的数据放入输出器中 self.urls.add_new_urls(new_urls) self.outer.conllect_data(new_data) if count >= 10:# 控制爬取的数量 break count += 1 except: print('爬虫失败一条') self.outer.output() print('爬虫结束。') if __name__ == '__main__': main_url = 'https://baike.baidu.com/item/Python/407313' mc = MainCrawler() mc.start_craw(main_url) 

 # URL管理器 class UrlManager(): def __init__(self): self.new_urls = set() # 待爬取 self.old_urls = set() # 已爬取 # 添加一个新的url def add_new_url(self, url): if url is None: return elif url not in self.new_urls and url not in self.old_urls: self.new_urls.add(url) # 批量添加url def add_new_urls(self, urls): if urls is None or len(urls) == 0: return else: for url in urls: self.add_new_url(url) # 判断是否有url def has_new_url(self): return len(self.new_urls) != 0 # 从待爬取的集合中获取一个url def get_new_url(self): new_url = self.new_urls.pop() self.old_urls.add(new_url) return new_url 

 from urllib import request # 网页下载器 class UrlDownLoader(): def down_load(self, url): if url is None: return None else: rt = request.Request(url=url, method='GET')   # 发GET请求 with request.urlopen(rt) as rp:         # 打开网页 if rp.status != 200: return None else: return rp.read()            # 读取网页内容 

 import re from urllib import parse from bs4 import BeautifulSoup # 网页解析器，使用BeautifulSoup class HtmlParser(): # 每个词条中，可以有多个超链接 # main_url指url公共部分，如“https://baike.baidu.com/” def _get_new_url(self, main_url, soup): # baike.baidu.com/ # 计算机程序设计语言 new_urls = set() # 解析出main_url之后的url部分 child_urls = soup.find_all('a', href=re.compile(r'/item/(\%\w{2})+')) for child_url in child_urls: new_url = child_url['href'] # 再拼接成完整的url full_url = parse.urljoin(main_url, new_url) new_urls.add(full_url) return new_urls # 每个词条中，只有一个描述内容，解析出数据（词条，内容） def _get_new_data(self, main_url, soup): new_datas = {} new_datas['url'] = main_url # 
计算机程序设计语言
... new_datas['title'] = soup.find('dd', class_='lemmaWgt-lemmaTitle-title').find('h1').get_text() # class="lemma-summary" label-module="lemmaSummary"... new_datas['content'] = soup.find('div', attrs={'label-module': 'lemmaSummary'}, class_='lemma-summary').get_text() return new_datas # 解析出url和数据（词条，内容） def parse(self, main_url, html_cont): if main_url is None or html_cont is None: return soup = BeautifulSoup(html_cont, 'lxml', from_encoding='utf-8') new_url = self._get_new_url(main_url, soup) new_data = self._get_new_data(main_url, soup) return new_url, new_data 

 # 输出器 class HtmlOuter(): def __init__(self): self.datas = [] # 先收集数据 def conllect_data(self, data): if data is None: return self.datas.append(data) return self.datas # 输出为HTML def output(self, file='output_html.html'): with open(file, 'w', encoding='utf-8') as fh: fh.write('') fh.write('') fh.write('') fh.write('') fh.write('') fh.write('') fh.write( '') fh.write('') fh.write('') fh.write('') fh.write('') fh.write('') for data in self.datas: fh.write('') fh.write(''.format(data['url'])) fh.write(''.format(data['title'])) fh.write(''.format(data['content'])) fh.write('') fh.write('
URL
词条
内容
{0}
{0}
{0}
') fh.write('') fh.write('')