python-爬虫-自带库抓取网页内容

痛定思痛。 2024-02-18 18:16 50阅读 0赞

python-爬虫-自带库抓取网页内容

版本：Python 2.7.10

python-爬虫-自带库抓取网页内容
    
    版本：Python 2.7.10 
    
    # -*- coding: utf-8 -*-
    import sys
    import lxml
    import requests
    import codecs
    import time
    from lxml import etree
    from lxml.html.clean import Cleaner
    
    reload(sys)
    sys.setdefaultencoding('utf8')  # 设置默认编码格式为'utf-8'
    
    #防止 print 不能输出中文
    if sys.stdout.encoding != 'UTF-8':
        sys.stdout = codecs.getwriter('utf-8')(sys.stdout, 'strict')
    if sys.stderr.encoding != 'UTF-8':
        sys.stderr = codecs.getwriter('utf-8')(sys.stderr, 'strict')
    
    
    demo_file="/Library/temp/demo.txt"
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    def save_tags(url):
        print '请求',url
        resp = requests.get(url) #请求
        print '请求完成'
        if not resp:
            print '无响应内容'
            return
    
        txt = resp.text
        print 'txt = ',type(txt)
    
        dom = etree.HTML(txt)
        print 'dom type = ',type(dom)
    
        xpath = '//div[@class=\'myClassName\']/a' //xpath
        result = dom.xpath(xpath)
        if not result or len(result)<1:
            print 'xpath = ',xpath,' 无内容'
            return
    
        n=0
        print '系统默认编码：',sys.getdefaultencoding()
        print '准备写入文件：',demo_file
        f = codecs.open(demo_file,'a+','utf-8')
        f.write('###{}\n'.format(url))
        for t in result:
            n=n+1
            txt = t.text.strip()
            print n,txt
            f.write('{}\n'.format(txt))
        f.close()
        print '写入文件结束：{}'.format(f.name)
    
    #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    def run():
        url_base = 'http://www.xxx.net/list?page='
        page_index=1
        end = 863
        print '爬取开始'
        for i in range(page_index,end+1):
            print '*'*30
            url = '{}{}'.format(url_base,i)
            save_tags(url)
            print 'sleep 中...'
            time.sleep(3)
            print '*'*30
        print '爬取结束'
    
    run()