python批量下载图片

import requests
from PIL import Image
from StringIO import StringIO

url = 'http://****/down.asp?id='
for x in xrange(59,49911):
	try:
		thisurl = url + str(x)
		r = requests.get(thisurl)
		filename = r.headers['content-disposition'][22:50]
		i = Image.open(StringIO(r.content))
		i.save(filename)
	except:
		print str(x) + ' failed'