快速学会python爬虫？python爬取大乐透开奖信息，python爬取影片信息

前期准备

• 先把所需要的爬虫的工具包准备好
• File -->>Setings -->> Project Interpreter //导入所需要的包，设置国内镜像
  
  

from bs4 import BeautifulSoup  #
import re
import urllib.request, urllib.error
import xlwt
from lxml import etree
import csv

爬取网页

• 分析目标网址的规律，例如体育**的大乐透开奖网址,每次往下翻页时只是 historykj_ 后面的数字在变化
  -'http://www.lottery.gov.cn/historykj/history_%s.jspx?_ltype=dlt'%i
• 定义爬取网页的函数，head伪装自己不让服务器发现你在爬取

def askURL(url):
    # 伪装自己是普通浏览网址
    head = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36"
    }
    request = urllib.request.Request(url, headers=head)
    html = ""
    try:
        response = urllib.request.urlopen(request)
        html = response.read().decode('GBK')
        #print(html)
    except urllib.error.URLError as e:
        if hasattr(e, "code"):
            print(e.code)
        if hasattr(e, "reason"):
            print(e.reason)

    return html

解析网页

• 分析所取目标数据的存放位置，之后利用工具包里的方法对我们所需要的数据进行提取
  

def getData():
    datalist = []
    for i in range(1, 101):  # 调用获取页面信息
        url = 'http://www.lottery.gov.cn/historykj/history_%s.jspx?_ltype=dlt' %i
        html = askURL(url)
        tree = etree.HTML(html)
        tr_list = tree.xpath('//div[@class="result"]/table/tbody/tr')  # 每页所有的tr
        td_list = tree.xpath('//div[@class="result"]/table/tbody/tr/td')  # 每页所有的td
        for tr_num in range(1, len(tr_list) + 1):
            #print(tr_num)
            qihao = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[1]//text()' % (tr_num))
            red1 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[2]//text()' % (tr_num))
            red2 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[3]//text()' % (tr_num))
            red3 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[4]//text()' % (tr_num))
            red4 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[5]//text()' % (tr_num))
            red5 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[6]//text()' % (tr_num))
            blue1 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[7]//text()' % (tr_num))
            blue2 = tree.xpath('//div[@class="result"]/table/tbody/tr[%s]/td[8]//text()' % (tr_num))
            data = qihao + red1 + red2 + red3 + red4 + red5 + blue1 + blue2
            datalist.append(data)
    return datalist

• 上面的方法适合用与存储在表格中的数据，下面的例子主要说明一个div封装一个整体的对象，例如影片信息
  

#影片规则
findlink = re.compile(r'<a href="(.*?)">')
#图片规则
findImag = re.compile(r'<img.*src="(.*?)"',re.S)#让换行符包含在字符中
#影片名规则
findTitle = re.compile(r'<span class="title">(.*)</span>')
#评分规则
findRating = re.compile(r'<span class="rating_num" property="v:average">(.*)</span>')
#评价人数
findJudge = re.compile(r'<span>(\d*)人评价</span>')
#影片概况
findInq = re.compile(r'<span class="inq">(.*)</span>')
#影片相关内容
findBd = re.compile(r'<p class="">(.*?)</p>',re.S)

# 爬取网页
def getData(baseurl):
    datalist = []
    for i in range(0, 10):       #调用获取页面信息
        url = baseurl + str(i * 25)
        html = askURL(url)
        # 逐一解析
        soup = BeautifulSoup(html,"html.parser")
        for item in soup.find_all('div',class_="item"):
            data=[]
            item=str(item)
            link = re.findall(findlink,item)[0]
            data.append(link)
            imgSrc=re.findall(findImag,item)[0]
            data.append(imgSrc)
            titles = re.findall(findTitle, item)
            if(len(titles)==2):
                ctitle=titles[0]
                data.append(ctitle)
                otitle=titles[1].replace("/","")
                data.append(otitle)
            else:
                data.append(titles[0])
                data.append('  ')
            rating = re.findall(findRating, item)[0]
            data.append(rating)
            judge = re.findall(findJudge, item)[0]
            data.append(judge)
            inq = re.findall(findInq, item)
            if(len(inq)!=0):
                inq = inq[0].replace("。","")
                data.append(inq)
            else:
                data.append(" ")
            bd = re.findall(findBd, item)[0]
            bd = re.sub('<br(\s+)?/>(\s+)?'," ",bd)
            bd = re.sub('/'," ",bd)
            data.append(bd.strip())#去掉前后空格
            datalist.append(data)
    return datalist

保存数据

def saveDate(datalist,savepath):
    book = xlwt.Workbook(encoding="utf-8",style_compression=0)
    sheet = book.add_sheet('豆瓣top250',cell_overwrite_ok=True)
    col=("电影链接","图片链接","影片中文名","影片国外名","评分","评价人数","概况","相关信息")
    for i in range(0,8):
        sheet.write(0,i,col[i])
    for i in range(0,250):
        print("第%d条" %(i+1))
        data = datalist[i]
        for j in range(0,8):
            sheet.write(i+1,j,data[j])
    book.save(savepath)

• 最后你就会欣然的得到你所想要的数据啦，在数据解析的时候比较难处理，需要所花费些功夫学习正则表达式以及那些工具包。