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=====================爬虫原理=====================
通过Python访问新闻首页,获取首页所有新闻链接,并存放至URL集合中。
逐一取出集合中的URL,并访问链接获取源码,解析出新的URL链接添加到集合中。
为防止重复访问,设置一个历史访问,用于对新添加的URL进行过滤。
解析DOM树,获取文章相关信息,并将信息存储到Article对象中。
将Article对象中的数据通过pymysql保存到数据库中。
每完成一次数据的存储,计数器增加并打印文章标题,否则打印错误信息。
如果集合中的URL全部读取完或数据数量达到设定值,程序结束。
=====================存储结构=====================
CREATE TABLE `news` ( `id` int(6) unsigned NOT NULL AUTO_INCREMENT, `url` varchar(255) NOT NULL, `title` varchar(45) NOT NULL, `author` varchar(12) NOT NULL, `date` varchar(12) NOT NULL, `about` varchar(255) NOT NULL, `content` text NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `url_UNIQUE` (`url`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
=====================脚本代码=====================
‘‘‘ 百度百家新闻收集 ‘‘‘ import re # 网络连接模块 import bs4 # DOM解析模块 import pymysql # 数据库连接模块 import urllib.request # 网络访问模块 # 配置参数 maxcount = 1000 # 数据数量 home = ‘http://baijia.baidu.com/‘ # 起始位置 # 数据库连接参数 db_config = { ‘host‘: ‘localhost‘, ‘port‘: ‘3310‘, ‘username‘: ‘woider‘, ‘password‘: ‘3243‘, ‘database‘: ‘python‘, ‘charset‘: ‘utf8‘ } url_set = set() # url集合 url_old = set() # 过期url # 获取首页链接 html = urllib.request.urlopen(home).read().decode(‘utf8‘) soup = bs4.BeautifulSoup(html, ‘html.parser‘) pattern = ‘http://\w+\.baijia\.baidu\.com/article/\w+‘ links = soup.find_all(‘a‘, href=re.compile(pattern)) for link in links: url_set.add(link[‘href‘]) # 文章类定义 class Article(object): def __init__(self): self.url = None self.title = None self.author = None self.date = None self.about = None self.content = None # 连接数据库 connect = pymysql.Connect( host=db_config[‘host‘], port=int(db_config[‘port‘]), user=db_config[‘username‘], passwd=db_config[‘password‘], db=db_config[‘database‘], charset=db_config[‘charset‘] ) cursor = connect.cursor() # 处理URL信息 count = 0 while len(url_set) != 0: try: # 获取链接 url = url_set.pop() url_old.add(url) # 获取代码 html = urllib.request.urlopen(url).read().decode(‘utf8‘)
# DOM解析 soup = bs4.BeautifulSoup(html, ‘html.parser‘) pattern = ‘http://\w+\.baijia\.baidu\.com/article/\w+‘ # 链接匹配规则 links = soup.find_all(‘a‘, href=re.compile(pattern)) # 获取URL for link in links: if link[‘href‘] not in url_old: url_set.add(link[‘href‘]) # 数据防重 sql = "SELECT id FROM news WHERE url = ‘%s‘ " data = (url,) cursor.execute(sql % data) if cursor.rowcount != 0: raise Exception(‘Data Repeat Exception: ‘ + url) # 获取信息 article = Article() article.url = url # URL信息 page = soup.find(‘div‘, {‘id‘: ‘page‘}) article.title = page.find(‘h1‘).get_text() # 标题信息 info = page.find(‘div‘, {‘class‘: ‘article-info‘}) article.author = info.find(‘a‘, {‘class‘: ‘name‘}).get_text() # 作者信息 article.date = info.find(‘span‘, {‘class‘: ‘time‘}).get_text() # 日期信息 article.about = page.find(‘blockquote‘).get_text() pnode = page.find(‘div‘, {‘class‘: ‘article-detail‘}).find_all(‘p‘) article.content = ‘‘ for node in pnode: # 获取文章段落 article.content += node.get_text() + ‘\n‘ # 追加段落信息 # 存储数据 sql = "INSERT INTO news( url, title, author, date, about, content ) " sql = sql + " VALUES (‘%s‘, ‘%s‘, ‘%s‘, ‘%s‘, ‘%s‘, ‘%s‘) " data = (article.url, article.title, article.author, article.date, article.about, article.content) cursor.execute(sql % data) connect.commit() except Exception as e: print(e) continue else: print(article.title) count += 1 finally: # 判断数据是否收集完成 if count == maxcount: break # 关闭数据库连接 cursor.close() connect.close()
=====================运行结果=====================
设置参数 maxcount = 10 , home = ‘http://baijia.baidu.com/‘
查询数据 SELECT title, author FROM python.news;
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原文地址:http://www.cnblogs.com/woider/p/5929442.html