淘宝商品比价定向爬虫

功能描述

• 目标：获取淘宝搜索页面的信息，提取其中名称和价格
• 理解：淘宝搜索接口 翻页的处理
• 技术路线：requests+re

搜索"书包"，浏览器起始页链接：
https://s.taobao.com/search?q=书包&commend=all&ssid=s5e&search_type=item&sourceId=tb.index&spm=a21bo.2017.201856taobaoitem.1&ie=utf8&initiative_id=tbindexz_20170306

第二页：

https://s.taobao.com/search?q=书包&commend=all&ssid=s5e&search_type=item&sourceId=tb.index&spm=a21bo.2017.201856taobaoitem.1&ie=utf8&initiative_id=tbindexz_20170306&bcoffset=4&ntoffset=4&p4ppushleft=1%2C48&s=44

每一页有44个商品。

程序的结构

• 步骤1 提交商品搜索请求，循环获取页面
• 步骤2 对于每个页面，提取商品名称和价格信息
• 步骤3 将信息输出在屏幕上

import requests
import re
def getHTMLText(url):
    try:
        r = requests.get(url, timeout = 30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        return r.text
    except:
        return ""
def parsePage(goodsList, html):
    try:
        priseList = re.findall(r'"view_price":"[d.]*"',html)
        titleList = re.findall(r'"raw_title":".*?"', html)
        for i in range(len(priseList)):
            prise = eval(priseList[i].split(':')[1])
            title = eval(titleList[i].split(':')[1])
            goodsList.append([prise, title])
    except:
        print("")
def printGoodsList(goodsList):
    tplt = "{:4}	{:8}	{:16}"
    print(tplt.format("序号", "价格", "商品名称"))
    count = 0
    for g in goodsList:
        count = count + 1
        print(tplt.format(count, g[0], g[1]))
def main():
    goods = '书包'
    depth = 3
    stard_url = 'https://s.taobao.com/search?q=' + goods
    infoList = []
    for i in range(depth):
        try:
            url = stard_url + '&s' + str(44 * i)
            html = getHTMLText(url)
            parsePage(infoList, html)
        except:
            continue
    printGoodsList(infoList)
main()

输出（部分）：