import ssl
import urllib2
i=1
import time
while(1):

 #不加的话，无法访问12306 
  ssl._create_default_https_context = ssl._create_unverified_context
  # headers = {"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.95 Safari/537.36"}
  # req = urllib2.Request("http://211.87.155.19/(yfsvlfreem4d0b553vkfzfzt)/CheckCode.aspx", headers=headers)
  # https: // www.zhihu.com / captcha.gif"https://kyfw.12306.cn/otn/passcodeNew/getPassCodeNew")
  u=urllib2.urlopen(req)
  data = u.read()
  f = open("C:/Users/123/Desktop/4/"+str(i)+".jpg",'wb')
  print i
  # time.sleep(1)#有时需要加延时，以防被封。
  i=i+1
  f.write(data)
  f.close()