爬取淘宝实例

import requests
import re


'''
目标：获取淘宝搜索页面的信息，提取其中的商品名称和价格 
理解： 淘宝的搜索接口 翻页的处理
技术路线：requests‐bs4‐re
'''


# 步骤1：提交商品搜索请求，循环获取页面
def get_html_text(url):
    headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0'}
    try:
        coo = 't=85db5e7cb0133f23f29f98c7d6955615; cna=3uklFEhvXUoCAd9H6ovaVLTG; isg=BM3NGT0Oqmp6Mg4qfcGPnvDY3-pNqzF2joji8w9SGWTYBu241_taTS6UdFrF3Rk0; miid=983575671563913813; thw=cn; um=535523100CBE37C36EEFF761CFAC96BC4CD04CD48E6631C3112393F438E181DF6B34171FDA66B2C2CD43AD3E795C914C34A100CE538767508DAD6914FD9E61CE; _cc_=W5iHLLyFfA%3D%3D; tg=0; enc=oRI1V9aX5p%2BnPbULesXvnR%2BUwIh9CHIuErw0qljnmbKe0Ecu1Gxwa4C4%2FzONeGVH9StU4Isw64KTx9EHQEhI2g%3D%3D; hng=CN%7Czh-CN%7CCNY%7C156; mt=ci=0_0; hibext_instdsigdipv2=1; JSESSIONID=EC33B48CDDBA7F11577AA9FEB44F0DF3'
        cookies = {}
        for line in coo.split(';'):  # 浏览器伪装
            name, value = line.strip().split('=', 1)
            cookies[name] = value
        r = requests.get(url, cookies=cookies, headers=headers, timeout=30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return ''


# 步骤2：对于每个页面，提取商品名称和价格信息
def parse_page(ilt, html):
    try:
        plt = re.findall(r'\"view_price\"\:\"[\d\.]*\"', html)  # findall搜索全部字符串，viex_price是源代码中表价格的值，后面的字符串为数字和点组成的字符串
        tlt = re.findall(r'\"raw_title\"\:\".*?\"', html)  # 找到该字符串和后面符合正则表达式的字符串
        for i in range(len(plt)):
            price = eval(plt[i].split(':')[1])  # re.split() 将一个字符串按照正则表达式匹配结果进行分割，返回列表类型
            title = eval(tlt[i].split(':')[1])  # 将re获得的字符串以：为界限分为两个字符串,并取第二个字符串
            ilt.append([price, title])
    except:
        print('')


# 步骤3：将信息输出到屏幕上
def print_goods_list(ilt):
    tplt = "{:4}\t{:8}\t{:16}"  # 长度为多少
    print(tplt.format('序号', '价格', '名称'))
    count = 0
    for g in ilt:
        count = count + 1
        print(tplt.format(count, g[0], g[1]))


def main():
    goods = '铅笔'
    depth = 3  # 要爬取几页
    start_url = 'https://s.taobao.com/search?q=' + goods
    info_list = []
    for i in range(depth):
        try:
            url = start_url + '&s=' + str(44*i)  # 44是淘宝每个页面呈现的宝贝数量
            html = get_html_text(url)
            parse_page(info_list, html)
        except:
            continue
    print_goods_list(info_list)


main()