本篇仅在于交流学习

解析页面

 可以采用xpath进行页面连接提取

进入页面

 通过进入的页面可以得到下载地址

步骤：

提取表页面模板链接——>进入连接——>提取页面内下载地址连接——>下载保存

headers = {
        'User-Agent': '用自己得头部'
    }
    response = requests.get(url=url, headers=headers).text  #解析页面
    tree = etree.HTML(response)
    #print(tree)
    page_list = tree.xpath('//div[@id="main"]/div/div/a') #捕获信息位置
    for li in page_list:
        page_list_url = li.xpath('./@href')[0]
        page_list_url = 'https:' + page_list_url  #提取页面地址
        #print(page_list_url)
        in_page = requests.get(url=page_list_url,headers=headers).text  #进入地址
        trees = etree.HTML(in_page)
        #print(trees)
        download_url = trees.xpath('//div[@class="clearfix mt20 downlist"]/ul/li/a/@href')[0]  #目的文件地址
        name = trees.xpath('//div[@class="ppt_tit clearfix"]/h1/text()')[0] + '.rar'  #文件名字
        name = name.encode('iso-8859-1').decode('utf-8')  #修改命名乱码
        #print(download_url)
        if not os.path.exists('./download'):  #保存
            os.mkdir('./download')
        download = requests.get(url=download_url,headers=headers).content
        page_name = 'download/' + name
        with open(page_name,'wb') as fp:
            fp.write(download)
            print(name,'end!')

分析网页之间联系：

实施多页面提取

    try:
        start = int(input('请输入要爬取到的尾页：'))
        if start == 1 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            print("爬取完毕")
        elif start == 2 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            url = 'https://sc.chinaz.com/jianli/free_2.html'
            get_page(url)
            print("爬取完毕")
        elif start >= 3 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            for i in range(2, start):
                url = 'https://sc.chinaz.com/jianli/free_%s.html' % (i * 1)
                get_page(url)
                print("爬取完毕")
    except ValueError:
        print('请输入数字：')

完整代码：

import requests
from lxml import etree
import os
def get_page(url):
    headers = {
        'User-Agent': '自己的头部'
    }
    response = requests.get(url=url, headers=headers).text  #解析页面
    tree = etree.HTML(response)
    #print(tree)
    page_list = tree.xpath('//div[@id="main"]/div/div/a') #捕获信息位置
    for li in page_list:
        page_list_url = li.xpath('./@href')[0]
        page_list_url = 'https:' + page_list_url  #提取页面地址
        #print(page_list_url)
        in_page = requests.get(url=page_list_url,headers=headers).text  #进入地址
        trees = etree.HTML(in_page)
        #print(trees)
        download_url = trees.xpath('//div[@class="clearfix mt20 downlist"]/ul/li/a/@href')[0]  #目的文件地址
        name = trees.xpath('//div[@class="ppt_tit clearfix"]/h1/text()')[0] + '.rar'  #文件名字
        name = name.encode('iso-8859-1').decode('utf-8')  #修改命名乱码
        #print(download_url)
        if not os.path.exists('./download'):  #保存
            os.mkdir('./download')
        download = requests.get(url=download_url,headers=headers).content
        page_name = 'download/' + name
        with open(page_name,'wb') as fp:
            fp.write(download)
            print(name,'end!')
def go():  #多页面选择
    try:
        start = int(input('请输入要爬取到的尾页：'))
        if start == 1 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            print("爬取完毕")
        elif start == 2 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            url = 'https://sc.chinaz.com/jianli/free_2.html'
            get_page(url)
            print("爬取完毕")
        elif start >= 3 :
            url = 'https://sc.chinaz.com/jianli/free.html'
            get_page(url)
            for i in range(2, start):
                url = 'https://sc.chinaz.com/jianli/free_%s.html' % (i * 1)
                get_page(url)
                print("爬取完毕")
    except ValueError:
        print('请输入数字：')
        go()

if __name__ == '__main__':
    go()

效果：