python3 爬取汽车之家所有车型数据操作步骤（更新版）

题记:

　　互联网上关于使用python3去爬取汽车之家的汽车数据（主要是汽车基本参数，配置参数，颜色参数，内饰参数）的教程已经非常多了，但大体的方案分两种：

　　1.解析出汽车之家某个车型的网页，然后正则表达式匹配出混淆后的数据对象与混淆后的js，并对混淆后的js使用pyv8进行解析返回正常字符，然后通过字符与数据对象进行匹配，具体方法见这位园友，传送门：https://www.cnblogs.com/my8100/p/js_qichezhijia.html （感谢这位大神前半部分的思路）

2.解析出汽车之家某个车型的网页，然后正则表达式匹配出混淆后的数据对象与混淆后的js，针对混淆后的js进行进行手动匹配，因为混淆的js大概分为8大类（无参数 返回常量，无参数 返回函数，参数等于返回值函数，无参数 返回常量，无参数 返回常量中间无混淆代码，字符串拼接时使无参常量，字符串拼接时使用返回参数的函数），然后通过正则表达式进行解析出8类内容并进行逐个替换，最终也会返回一个带有顺序的字符串，将这个字符串与前边的数据对象再次替换，最终数据对象中的所有span都会被替换成中文，具体操作见园友的地址，传送门:https://www.cnblogs.com/dyfblog/p/6753251.html （感谢这位大神前半部分的思路）

不过鉴于作者技术有限，上述的两种方案，我都没有完整的执行完成，哪怕花了一周的时间也没有，但是没有办法，谁让我是一个很爱钻牛角尖的人呢，下一步提出我自己琢磨出来的方案，流程上稍微有点复杂，但是稳打稳扎，还是可以爬出来的，好了话不多说了，贴出步骤；

1.获取所有车型的网页，保存到本地：

import bs4
import requests as req
'''
第一步，下载出所有车型的网页。
'''
def mainMethod():
    '''
    解析汽车之家所有车型数据保存到D盘
    '''
    li = [chr(i) for i in range(ord("T"),ord("Z")+1)]
    firstSite="https://www.autohome.com.cn/grade/carhtml/"
    firstSiteSurfixe=".html"
    secondSite = "https://car.autohome.com.cn/config/series/"
    secondSiteSurfixe = ".html"

    for a in li:
        if a is not None:
            requestUrl = firstSite+a+firstSiteSurfixe
            print(requestUrl)
            #开始获取每个品牌的车型
            resp = req.get(requestUrl)
            # print(str(resp.content,"gbk"))
            bs = bs4.BeautifulSoup(str(resp.content,"gbk"),"html.parser")
            bss = bs.find_all("li")
            con = 0
            for b in bss:
                d = b.h4
                if d is not None:
                    her = str(d.a.attrs['href'])
                    her = her.split("#")[0]
                    her = her[her.index(".cn")+3:].replace("/",'')
                    if her is not None:
                        secSite = secondSite +her + secondSiteSurfixe
                        print("secSite="+secSite)
                        # print(secSite)
                        #奥迪A3
                        if her is not None:
                            resp = req.get(secSite)
                            text = str(resp.content,encoding="utf-8")
                            print(a)
                            fil = open("d:\\autoHome\\html\\"+str(her),"a",encoding="utf-8")
                            fil.write(text)
                    con = (con+1)
            else:
                print(con)
if __name__ =="__main__":
    mainMethod()

2.解析出每个车型的关键js并拼装成一个html,保存到本地。

import os
import re
'''
第二步，解析出每个车型的关键js拼装成一个html
'''
if __name__=="__main__":
    print("Start...")
    rootPath = "D:\\autoHome\\html\\"
    files = os.listdir(rootPath)
    for file in files:
        print("fileName=="+file.title())
        text = ""
        for fi in open(rootPath+file,'r',encoding="utf-8"):
            text = text+fi
        else:
            print("fileName=="+file.title())
        #解析数据的json
        alljs = ("var rules = '2';"
                 "var document = {};"
                 "function getRules(){return rules}"
                 "document.createElement = function() {"
                 "      return {"
                 "              sheet: {"
                 "                      insertRule: function(rule, i) {"
                 "                              if (rules.length == 0) {"
                 "                                      rules = rule;"
                 "                              } else {"
                 "                                      rules = rules + '#' + rule;"
                 "                              }"
                 "                      }"
                 "              }"
                 "      }"
                 "};"
                 "document.querySelectorAll = function() {"
                 "      return {};"
                 "};"
                 "document.head = {};"
                 "document.head.appendChild = function() {};"

                 "var window = {};"
                 "window.decodeURIComponent = decodeURIComponent;")
        try:
            js = re.findall('(\(function\([a-zA-Z]{2}.*?_\).*?\(document\);)', text)
            for item in js:
                alljs = alljs + item
        except Exception as e:
            print('makejs function exception')

        newHtml = "<html><meta http-equiv='Content-Type' content='text/html; charset=utf-8' /><head></head><body>    <script type='text/javascript'>"
        alljs = newHtml + alljs+" document.write(rules)</script></body></html>"
        f = open("D:\\autoHome\\newhtml\\"+file+".html","a",encoding="utf-8")
        f.write(alljs)
        f.close()

3.解析出每个车型的数据json，比如var config  ,var option , var bag  var innerbag..但我就解析了基本信息跟配置信息，其他的无所谓。

import os
import re
'''
第三步 解析出每个车型的数据json，保存到本地。
'''
if __name__=="__main__":
    print("Start...")
    rootPath = "D:\\autoHome\\html\\"
    files = os.listdir(rootPath)
    for file in files:
        print("fileName=="+file.title())
        text = ""
        for fi in open(rootPath+file,'r',encoding="utf-8"):
            text = text+fi
        else:
            print("fileName=="+file.title())
        #解析数据的json
        jsonData = ""
        config = re.search('var config = (.*?){1,};',text)
        if config!= None:
            print(config.group(0))
            jsonData = jsonData+ config.group(0)
        option = re.search('var option = (.*?)};',text)
        if option != None:
            print(option.group(0))
            jsonData = jsonData+ option.group(0)
        bag = re.search('var bag = (.*?);',text)
        if bag != None:
            print(bag.group(0))
            jsonData = jsonData+ bag.group(0)
        # print(jsonData)
        f = open("D:\\autoHome\\json\\"+file,"a",encoding="utf-8")
        f.write(jsonData)
        f.close()

4.生成样式文件，保存 到本地。

import os
from selenium import webdriver

'''
    第四步，浏览器执行第二步生成的html文件，抓取执行结果，保存到本地。
'''
class Crack():
    def __init__(self,keyword,username,passod):
        self.url = 'https://www.baidu.com'
        self.browser = webdriver.Chrome('E:\work\ChromePortable\App\Google Chrome\chromedriver.exe')

if __name__=="__main__":
    lists = os.listdir("D:/autoHome/newHtml/")
    crack = Crack('测试公司','17610177519','17610177519')
    for fil in lists:
        file = os.path.exists("D:\\autoHome\\content\\"+fil)
        if file :
            print('文件已经解析。。。'+str(file))
            continue
        print(fil)
        crack.browser.get("file:///D:/autoHome/newHtml/"+fil+"")
        text = crack.browser.find_element_by_tag_name('body')
        print(text.text)
        f = open("D:\\autoHome\\content\\"+fil,"a",encoding="utf-8")
        f.write(text.text)
    else:
        f.close()
        crack.browser.close()

5.读取样式文件，匹配数据文件，生成正常数据文件

 import os
import re
'''
第五步 匹配样式文件与json数据文件，生成正常的数据文件。
'''
if __name__ =="__main__":
    rootPath = "D:\\autoHome\\json\\"
    listdir = os.listdir(rootPath)
    for json_s in listdir:
        print(json_s.title())
        jso = ""
        #读取json数据文件
        for fi in open(rootPath+json_s,'r',encoding="utf-8"):
            jso = jso+fi
        content = ""
        #读取样式文件
        spansPath = "D:\\autoHome\\content\\"+json_s.title()+".html"
        # print(spansPath)
        for spans in  open(spansPath,"r",encoding="utf-8"):
            content = content+ spans
        print(content)
        #获取所有span对象
        jsos = re.findall("<span(.*?)></span>",jso)
        num = 0
        for js in jsos:
            print("匹配到的span=>>"+js)
            num = num +1
            #获取class属性值
            sea = re.search("'(.*?)'",js)
            print("匹配到的class==>"+sea.group(1))
            spanContent = str(sea.group(1))+"::before { content:(.*?)}"
            #匹配样式值
            spanContentRe = re.search(spanContent,content)
            if spanContentRe != None:
                if sea.group(1) != None:
                    print("匹配到的样式值="+spanContentRe.group(1))
                    jso = jso.replace(str("<span class='"+sea.group(1)+"'></span>"),re.search("\"(.*?)\"",spanContentRe.group(1)).group(1))
        print(jso)
        fi = open("D:\\autoHome\\newJson\\"+json_s.title(),"a",encoding="utf-8")
        fi.write(jso)
        fi.close()

6.到前五步已经可以看到json数据文件都已经是混淆前的了，说明已经爬取成功了。

7.读取数据文件，生成excel

import json
import os
import re
import xlwt
'''
第七步读取数据文件，生成excel
'''
if __name__ == "__main__":
    rootPath = "D:\\autoHome\\newJson\\"
    workbook = xlwt.Workbook(encoding = 'ascii')#创建一个文件
    worksheet = workbook.add_sheet('汽车之家')#创建一个表
    files = os.listdir(rootPath)
    startRow = 0
    isFlag = True #默认记录表头
    for file in files:
        list = []
        carItem = {}
        print("fileName=="+file.title())
        text = ""
        for fi in open(rootPath+file,'r',encoding="utf-8"):
            text = text+fi
        # else:
            # print("文件内容=="+text)
        #解析基本参数配置参数，颜色三种参数，其他参数
        config = "var config = (.*?);"
        option = "var option = (.*?);var"
        bag = "var bag = (.*?);"

        configRe = re.findall(config,text)
        optionRe = re.findall(option,text)
        bagRe = re.findall(bag,text)
        for a in configRe:
            config = a
        print("++++++++++++++++++++++\n")
        for b in optionRe:
            option = b
            print("---------------------\n")
        for c in bagRe:
            bag = c
        # print(config)
        # print(option)
        # print(bag)

        # print(bag)
        try:
            config = json.loads(config)
            option = json.loads(option)
            bag = json.loads(bag)
            # print(config)
            # print(option)
            # print(bag)
            path = "D:\\autoHome\\autoHome.xls"

            configItem = config['result']['paramtypeitems'][0]['paramitems']
            optionItem = option['result']['configtypeitems'][0]['configitems']
        except Exception as e:
            f =  open("D:\\autoHome\\异常数据\\exception.txt","a",encoding="utf-8")
            f.write(file.title()+"\n")
            continue

        #解析基本参数
        for car in configItem:
            carItem[car['name']]=[]
            for ca in car['valueitems']:
                carItem[car['name']].append(ca['value'])
        # print(carItem)
        #解析配置参数
        for car in optionItem:
            carItem[car['name']]=[]
            for ca in car['valueitems']:
                carItem[car['name']].append(ca['value'])

        if isFlag:
            co1s = 0

            for co in carItem:
                co1s = co1s +1
                worksheet.write(startRow,co1s,co)
            else:
                startRow = startRow+1
                isFlag = False

        #计算起止行号
        endRowNum = startRow + len(carItem['车型名称']) #车辆款式记录数
        for row in range(startRow,endRowNum):
            print(row)
            colNum = 0
            for col in carItem:

                colNum = colNum +1
                print(str(carItem[col][row-startRow]),end='|')
                worksheet.write(row,colNum,str(carItem[col][row-startRow]))

        else:
            startRow  = endRowNum
    workbook.save('d:\\autoHome\\Mybook.xls')

8.最后打开excel文件，给你们看看。

数据量大概有8300的样子。以后买车就用这个参考了。