Question

I’m new to Django and Python.

When I move my code from my local dev box to my site on Webfaction it seems to break my code. If I then remove (context_instance=RequestContext(request)) from my main application views.py it seems to fix the problem. If later I put the line back in it works fine.

return render_to_response('template.html', {"var": var},**context_instance=RequestContext(request)**)

Error email from webhost:

Traceback (most recent call last):

 File "/home/hhadmin69/webapps/django/lib/python2.5/django/core/handlers/base.py", line 92, in get_response
   response = callback(request, *callback_args, **callback_kwargs)

 File "/home/hhadmin69/webapps/django/hhv3/article/views.py", line 32, in post_index
   return render_to_response('article/post_index.html', {"posts": posts},context_instance=RequestContext(request))

 File "/home/hhadmin69/webapps/django/lib/python2.5/django/template/context.py", line 107, in __init__
   self.update(processor(request))

 File "/home/hhadmin69/webapps/django/hhv3/context_processors.py", line 12, in latest_tweet
   tweet = twitter.Api().GetUserTimeline( settings.TWITTER_USER )[0]

 File "build\bdist.win32\egg\twitter.py", line 1414, in GetUserTimeline

 File "build\bdist.win32\egg\twitter.py", line 2032, in _FetchUrl

 File "/usr/local/lib/python2.5/urllib2.py", line 387, in open
   response = meth(req, response)

 File "/usr/local/lib/python2.5/urllib2.py", line 498, in http_response
   'http', request, response, code, msg, hdrs)

 File "/usr/local/lib/python2.5/urllib2.py", line 425, in error
   return self._call_chain(*args)

 File "/usr/local/lib/python2.5/urllib2.py", line 360, in _call_chain
   result = func(*args)

 File "/usr/local/lib/python2.5/urllib2.py", line 506, in http_error_default
   raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)

HTTPError: HTTP Error 400: Bad Request


 'SERVER_SOFTWARE': 'Apache/2.2.12 (Unix) mod_wsgi/2.5 Python/2.5.4',

context_processors.py

from datetime import datetime
from django.conf import settings
from django.core.cache import cache
import twitter

from django.template import Library, Node, TemplateSyntaxError

def latest_tweet( request ):
    tweet = cache.get( 'tweet' )

    if tweet:
        return {"tweet": tweet}
    try:
        tweet = twitter.Api().GetUserTimeline( settings.TWITTER_USER )[0]
        tweet.date = datetime.strptime( tweet.created_at, "%a %b %d %H:%M:%S +0000 %Y" )
        cache.set( 'tweet', tweet, settings.TWITTER_TIMEOUT )
    except (RuntimeError, TypeError, NameError):
        pass    

    return {"tweet": tweet}

THANK YOU!!

Answer 1

It’s not RequestContext – context only triggers tweeter lookup which actually fails. If you put the line back in it works? That could only mean that your twitter lookup problem is inconsistent, as is possible with any HTTP lookups, so you should take care of possible network problems by also handling IOError (which is a parent of HTTPError and URLError which are thrown by urllib2).

try:
    tweet = twitter.Api().GetUserTimeline( settings.TWITTER_USER )[0]
except IOError, e:
    logging.error(e) #or just print, dont know how you log

Analyze exactly how and when it fails and try to find the problem. Looking at the actual URL which urllib2 tries to access may help, too.