Question

Without any code changing, my django app started throwing an exception while loading the WSGI script. I’m using django 1.3 with python 2.7, and the top-level .wsgi is essentially unmodified from the default:

import os
import sys

from django.core.handlers.wsgi import WSGIHandler

os.environ['DJANGO_SETTINGS_MODULE'] = 'api.settings'
application = WSGIHandler()

It started producing these errors on any request, as reported by Apache:

mod_wsgi (pid=3283): Target WSGI script '/home/beder/webapps/api/api.wsgi' cannot be loaded as Python module.
mod_wsgi (pid=3283): Exception occurred processing WSGI script '/home/beder/webapps/api/api.wsgi'.
Traceback (most recent call last):
  File "/home/beder/webapps/api/api.wsgi", line 4, in <module>
    from django.core.handlers.wsgi import WSGIHandler
  File "/home/beder/webapps/api/lib/python2.7/django/core/handlers/wsgi.py", line 10, in <module>
    from django import http
  File "/home/beder/webapps/api/lib/python2.7/django/http/__init__.py", line 122, in <module>
    from django.utils.http import cookie_date
  File "/home/beder/webapps/api/lib/python2.7/django/utils/http.py", line 7, in <module>
    from email.Utils import formatdate
  File "/usr/local/lib/python2.7/email/__init__.py", line 79, in __getattr__
    __import__(self.__name__)
  File "/usr/local/lib/python2.7/email/utils.py", line 27, in <module>
    import random
  File "/usr/local/lib/python2.7/random.py", line 47, in <module>
    from os import urandom as _urandom
ImportError: cannot import name urandom

I restarted the server, and it now works normally (no errors). I’m at a loss for what to do – I want to make sure this doesn’t happen again, but it’s not happening now, and I have no idea why that import error appeared.

Answer 1

Are you executing Django inside a virtualenv? Did you updated or upgraded your system? If so and you upgraded to Python 2.7 from Python 2.6 for example you need to regenerate the virtualenv:

$ virtualenv [your-options] [your-django-project-directory]