爬取空气质量1

import urllib.request
import requests
import csv
import re
from lxml import etree


url='http://www.air-level.com'
response=urllib.request.urlopen(url+'/').read().decode()
hrefs=re.findall(r'<a href="(.*?)">',response)
k=1
listw=[]
header=['监测站','AQL','空气质量等级','PM2.5','PM10','主要污染物']
for i in hrefs:
    urls=url + i
    headers = {
        'User-Agent': 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36 QIHU 360SE'}
    response=requests.get(urls, headers=headers)
    #print(response.raise_for_status)
    if str(response.raise_for_status)=='<bound method Response.raise_for_status of <Response [200]>>':
      html=etree.HTML(response.text)
      print(html)
      name =html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[1]/text()')
      aql=html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[2]/text()')
      rank=html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[3]/span/text()')
      pm2=html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[4]/text()')
      pm10=html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[5]/text()')
      po=html.xpath('/html/body/div[1]/div[3]/div[1]/div[2]/table/tr/td[6]/text()')
      with open('C:\\Users\\lenovo\\Desktop\\ookk.csv','a+',newline='',encoding='utf-8')as f:
         writers=csv.writer(f)
         for j in range(0,len(name)-1):
            if k == 1:
                k = k-1
                writers.writerow(header)
                listw = [name[j], aql[j], rank[j], pm2[j],pm10[j],po[j]]
                writers.writerow(listw)
            else:
                if rank[j]=='优':
                    listw = [name[j], aql[j], rank[j], pm2[j], pm10[j]]
                    writers.writerow(listw)
                else:
                      if aql[j]=='-':
                         listw = [name[j]]
                         writers.writerow(listw)
                      else:
                          listw = [name[j], aql[j], rank[j], pm2[j], pm10[j], po[j]]
                          writers.writerow(listw)