服务器上的 django 应用程序：没有名为“django.urls”的模块

Question

I have a Django (v1.11.6) app on my Ubuntu server and was using Python v2.7 .

I am now using Python 3.5 (not using virtualenv ), however when I run sudo service apache2 restart I get the following error in my browser:

ImportError at /
No module named 'django.urls'
Request Method: GET
Request URL:    https://dev.ga.coach/
Django Version: 1.8.7
Exception Type: ImportError
Exception Value:    
No module named 'django.urls'

Python Executable:  /usr/bin/python3
Python Version: 3.5.2

When I run python3 manage.py runserver I get no error.

When I execute sudo pip freeze | grep -i 'django' sudo pip freeze | grep -i 'django' I get the following:

Django==1.11.6
django-allauth==0.33.0
django-filter==1.0.4
django-rest-auth==0.9.1
djangorestframework==3.6.3
djangorestframework-jwt==1.11.0

Answer 1

Your apache config is using Django 1.8.7 as you can see in your error. And you're using a newer method for including urls ( url(r'^users/', include('users.urls'), name='users') inside urls.py which wasn't supported in Django 1.8.

Since your switched from python 2.7 to python 3.5 it's quite likely your mod_wsgi module is still the one compiled with python 2.7. Here's what the WSGI docs say about that:

When using a Python virtual environment with mod_wsgi, it is very important that it has been created using the same Python installation that mod_wsgi was originally compiled for. It is not possible to use a Python virtual environment to force mod_wsgi to use a different Python version, or even a different Python installation.

You cannot for example force mod_wsgi to use a Python virtual environment created using Python 3.5 when mod_wsgi was originally compiled for Python 2.7. This is because the Python library for the Python installation it was originally compiled against is linked directly into the mod_wsgi module. In other words, Python is embedded within mod_wsgi. When mod_wsgi is used it does not run the command line python program to run the interpreter and thus why you can't force it to use a different Python installation.

So try re-installing mod_wsgi using python 3.5. That should then be able to find the Django package you installed with python 3.5.