Python3 抓取网页中的图片

import urllib.requestimport socketimport reimport sysimport ostargetDir = r"C:\Users\elqstux\Desktop\pic"def destFile(path):    if not os.path.isdir(targetDir):        os.mkdir(targetDir)    pos = path.rindex('/')    t = os.path.join(targetDir, path[pos+1:])    return tif __name__ == "__main__":    hostname = "http://www.douban.com"    req = urllib.request.Request(hostname)    webpage = urllib.request.urlopen(req)    contentBytes = webpage.read()    for link, t in set(re.findall(r'(http:[^\s]*?(jpg|png|gif))', str(contentBytes))):        print(link)        urllib.request.urlretrieve(link, destFile(link))