python爬取淘宝商品信息以及正则表达式

正则表达式

1.正则表达式：用来简洁表达一组字符串的表达式；
2.一行胜千言
3.‘PY’开头，后续存在不多于10个字符，后续字符不能是‘P’或者‘Y’；
4.通用字符串表达框架
5.简洁表达一组字符串的表达式；
6.针对字符串表达“简洁”和“特征”思想的工具；
7.判断某字符串的特征归属；
8.正则表达式的作用：
（1）表达文本类型的特征；
（2）同时查找或替换一组字符串；
（3）匹配字符串的全部或部分；
9.正则表达式的语法：正则表达式由字符和操作符构成；

Re库

1.Re库是python的标准库，主要用于字符串匹配；
2.调用方法：import re
3.正则表达式的表示类型：raw string类型（原生字符串类型:不包含转义符的字符串），re库采用raw string类型表达正则表达式，表示为：r’text’。

爬虫案例:淘宝信息爬虫

源代码：

python爬取淘宝商品信息

import requests 
import re

def getHTMLText(url):
    try:
        headers = \
        {
            'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36',
            'Cookie':'cna=rMvxE5KEPygCAXyYz3ySaWmo; tracknick=t_1499512875051_0521; tg=0; enc=WKhhjIEw5hx%2FRJKFnn7FwgHiYOazZBxLXrZQxncWTkMGcJ%2FkYbmGPDdtKo0VQ3Pqd9q0t77d6W3kwCKBUcYK4Q%3D%3D; hng=CN%7Czh-CN%7CCNY%7C156; x=e%3D1%26p%3D*%26s%3D0%26c%3D0%26f%3D0%26g%3D0%26t%3D0%26__ll%3D-1%26_ato%3D0; miid=973723631245416133; _cc_=U%2BGCWk%2F7og%3D%3D; t=b163eabb82d02ed05c037f22b430e91d; _m_h5_tk=481d0a05dd192d8490270d96237044d0_1580035714907; _m_h5_tk_enc=033a7edcd36664ca087d0a9e2b68acad; thw=cn; cookie2=1e6d43b1fa16858277b7385b64632dba; v=0; _tb_token_=d718679859e7; alitrackid=www.taobao.com; lastalitrackid=www.taobao.com; tk_trace=oTRxOWSBNwn9dPyorMJE%2FoPdY8zfvmw%2Fq5hp3RMAXcOSWZRv%2Bdy3Y1Ffj%2BbBAKFNk3aFpDRhDhnCVve48be9H5AOdMUXXEylXnm0Q49nlGsj3PY1O884fhm6v0VfEVhZ5wI1KNodEvR27oygtLOLX%2BjbWkDju%2FQFwnS5y86YEaoG3LoZjXHpkkovxTYhtWaTDUT7efY1thqtNaIndtMWz12iDviwGLoEbaB3dB3ZAxcvgzFMas6YTWBJdDKDVRVZJeFjYlPDKBW1YzLfObRJHGChPw%3D%3D; l=cBEyVmERvs4cQzXCBOfZCuI8Lu7t4BAX1sPzw4OMZICP_W5FH1Y1WZmFtkLwCnGVLs9W-3Jt3efYB88UHy4Eh2nk8b8CgsDd.; isg=BFFRj2M0605-AwU6Xs8J9i6yYF3rvsUwyvi1KzPgFJjO2mEseQ98Acl4eK48Ul1o; JSESSIONID=3E36719A923A7E4CC75A68F538DC261D'
        }
        r = requests.get(url,headers = headers,timeout = 30)
        r.raise_for_status()
        r.encoding = r.apparent_encoding
        # print(r.text)
        return r.text
    except:
        return ""

def parasePage(ilt,html): # 解析网页代码
    try:
        # "view_price":"559.00" 正则表达式匹配
        plt = re.findall(r'\"view_price\"\:\"[\d\.]*\"',html)
        # "raw_title":"双肩包男士大容学生" 正则表达式匹配
        tlt = re.findall(r'\"raw_title\"\:\".*?\"',html)
        for i in range(len(plt)):
            price = eval(plt[i].split(':')[1])
            title = eval(tlt[i].split(':')[1])
            ilt.append([price,title])
    except:
        print("")

def printGoodsList(ilt):
    tplt = "{:4}\t{:8}\t{:16}"
    print(tplt.format("序号","价格","商品名称"))
    count = 0
    for g in ilt:
        count += 1
        print(tplt.format(count,g[0],g[1]))

def main():
    goods = "书包"
    depth = 2 #爬取的页面数量
    start_url = " https://s.taobao.com/search?q="+goods
    infoList = []
    for i in range(depth):
        try:
            url = start_url + '&s=' + str(44*i)
            html = getHTMLText(url)
            print(url)
            parasePage(infoList,html)
        except:
            continue
    printGoodsList(infoList)

main()

爬取结果展示

由于本人水平有限，欢迎各位大佬评论！