如何使用python取消缩短URL？

在该问题中使用评分最高的答案（而非公认的答案）：

# This is for Py2k.  For Py3k, use http.client and urllib.parse instead, and# use // instead of / for the divisionimport httplibimport urlparsedef unshorten_url(url):    parsed = urlparse.urlparse(url)    h = httplib.HTTPConnection(parsed.netloc)    resource = parsed.path    if parsed.query != "":        resource += "?" + parsed.query    h.request('HEAD', resource )    response = h.getresponse()    if response.status/100 == 3 and response.getheader('Location'):        return unshorten_url(response.getheader('Location')) # changed to process chains of short urls    else:        return url