import urllib
import re
import os
path = "set your path or '.'"
i = 1
content = True
while content:
dir = os.listdir(path)
for file in dir:
if file[:-4].isdigit():
if int(file[:-4]) >= i:
i = int(file[:-4])+1
while content:
url = "http://www.xkcd.com/"+str(i)+"/"
rd = urllib.urlopen(url)
data = rd.read()
res = re.search("/comics/[a-z0-9_()]*.(jpg|png)", data)
if res:
imgurl = "http://imgs.xkcd.com"+res.group()
image = urllib.URLopener()
image.retrieve(imgurl, path+str(i)+imgurl[-4:])
else:
if re.search("Not Found", data) and i != 404:
content = False
i += 1