Python urllib2: Reading content body even during HTTPError exception?

I'm using urllib2 to fetch a a page via HTTP. Sometimes the resource throws a HTTP error 400 (Bad Request) when my request contains an error. However, that response also contains an XML element 开发者_运维技巧that gives a detailed error message. It would be very handy to be able to see that error rather than just the HTTPError exception returned by urllib2.

How do I return the document contents in spite of the exception?

import urllib2
try:
    request = urllib2.Request('http://www.somesite.com')
    response = urllib2.urlopen(req)
except urllib2.HTTPError as e:
    error_message = e.read()
    print error_message

You can treat the error as a response.

http://www.voidspace.org.uk/python/articles/urllib2.shtml#httperror

When an error is raised the server responds by returning an HTTP error code and an error page. You can use the HTTPError instance as a response on the page returned. This means that as well as the code attribute, it also has read, geturl, and info, methods.

You can read the response message from the HTTPError exception.

Python3 example

import urllib.request

try:
    request = urllib.request.Request('http://httpstat.us/418', headers={'Accept': 'text/plain', 'User-Agent': ''})
    with urllib.request.urlopen(request) as page:
        print('success: ' + page.read().decode())
except urllib.error.HTTPError as httpError:
        error = httpError.read().decode()
        print('error: ' + error)