检查 URL 是否有效

#---------- check_url.py ----------#
from httplib import HTTP
from urlparse import urlparse

def checkURL(url):
 p = urlparse(url)
 h = HTTP(p[1])
 h.putrequest('HEAD', p[2])
 h.endheaders()
 return h.getreply()

if __name__ == '__main__':
for url in ('http://msnbc.com/nonsense','http://msnbc.com/',
           'http://w3c.org/','http://w3c.org/nonsense',
           'http://w3c.org/Consortium/','http://ibm.com/',
           'http://ibm.com/nonsense'):
 print url, checkURL(url)[:2]

------------------------------------------------------------------------
% python check_url.py
http://msnbc.com/nonsense (200, 'OK')
http://msnbc.com/ (302, 'Object moved')
http://w3c.org/ (301, 'Moved Permanently')
http://w3c.org/nonsense (301, 'Moved Permanently')
http://w3c.org/Consortium/ (301, 'Moved Permanently')
http://ibm.com/ (200, 'OK')
http://ibm.com/nonsense (404, 'Not Found')

　　虽然还有点小问题，不是100%准确。不过对于大多数情况是没有问题的。