错误方法：
import urllib2
req = urllib2.Request('http://127.0.0.1/longerrorpage')
try:
response=urllib2.urlopen(req)
except Exception,e:
print e, response.read()
HTTP Error 404: Not Found正确方法：
import urllib2
req = urllib2.Request('http://127.0.0.1/longerrorpage')
try:
response=urllib2.urlopen(req)
except urllib2.HTTPError,e:
print e.code
print e.reason
print e.geturl()
print e.read()
404 Not Found http://127.0.0.1/longerrorpage <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>404 Not Found</title> </head><body> <h1>Not Found</h1> <p>The requested URL /longerrorpage was not found on this server.</p> <hr> <address>Apache/2.2.22 (Ubuntu) Server at 127.0.0.1 Port 80</address> </body></html>