How do I properly set PYTHONPATH when invoking the Django Python shell?

Question

I'm using Python 3.9.9 for a Django 3 project. I would like to invoke my Python shell, via "python3 manage.py shell", so I have set these variables ...

$ echo $PYTHONSTARTUP
/home/myuser/cbapp/shell_startup.py
$ echo $PYTHONPATH/myuser
/home/myuser/cbapp/

My startup script is very simple ...

$ cat /home/myuser/cbapp/shell_startup.py 
from cbapp.services import *
from cbapp.models import *

However, when I change to my project directory, activate my virtual environment, and attempt to invoke the shell, I get these errors complaining about not being able to find Django ...

$ cd /home/myuser/cbapp
$ ./venv/bin/activate
$ python3 manage.py shell
Traceback (most recent call last):
  File "/home/myuser/cbapp/manage.py", line 10, in main
    from django.core.management import execute_from_command_line
ModuleNotFoundError: No module named 'django'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/myuser/cbapp/manage.py", line 21, in <module>
    main()
  File "/home/myuser/cbapp/manage.py", line 12, in main
    raise ImportError(
ImportError: Couldn't import Django. Are you sure it's installed and available on your PYTHONPATH environment variable? Did you forget to activate a virtual environment?

However, Django has already been installed in my virtual environment ...

$ ls /home/myuser/cbapp/venv/lib/python3.9/site-packages/django/
apps  conf     core  dispatch  http         __main__.py  __pycache__   template      test  utils
bin   contrib  db    forms     __init__.py  middleware   shortcuts.py  templatetags  urls  views

What else do I need to do to start my shell successfully?

Answer 1

./venv/bin/activate? That would execute a venv virtual environment in a subshell, not in your current shell.

The documentation recommends:

source ./venv/bin/activate

And make sure your PYTHONPATH include the directory where Django is installed. If Django is installed in the virtual environment, then PYTHONPATH should include the path to the site-packages directory of the virtual environment. However, it is typically not necessary to set PYTHONPATH if you have activated your virtual environment correctly.

Once your virtual environment is activated, you should be able to run the Django shell using the following command from the root directory of your Django project (/home/myuser/cbapp/ in your case):

python3 manage.py shell

Verify the Django installation within your virtual environment: python3 -m django --version. If Django is installed correctly, this command will return the installed version of Django.

Make sure the DJANGO_SETTINGS_MODULE environment variable is set correctly. This variable should point to your settings file, usually in the format myproject.settings. You can set this variable in your shell or add it to your shell_startup.py file with:

import os
os.environ['DJANGO_SETTINGS_MODULE'] = 'cbapp.settings'

Answer 2

I think you can try reinstalling Django in your virtual environment like this

python3 -m pip install -U Django

and if you still encounter the same error,you have to activated your virtual environment before running the Python shell, so first of all run this:

source ./venv/bin/activate

and check if the PYTHONPATH environment variable is correctly set or not.

echo $PYTHONPATH

if the output was empty you can set it manually like this :

export PYTHONPATH=/home/myuser/cbapp/ 

ok, now test it again :

python3 manage.py shell

Answer 3

Looks like your venv is not working correctly and suggest that remove them and recreate the virtualenv

• virtualenv venv --python3={your desired interpreter}

• Install your packages after activating new venv source activate venv/bin/acitvate

• Please confirm Django installation again using pip list | grep Django. If you couldn't find then reinstall.

• Check manage.py Sometimes, the shebang #!/usr/bin/env python3 at the top of manage.py can cause issues if it points to a global Python instead of your virtual environment. You can remove the shebang or make sure the virtual environment is always active when you run the script.

Answer 4

Here are some steps I think.

1. you need to install the python.exe but at that time, you should to check the 'checkBox' button because if you don't this, you need to set the env variable. But if you check, it will be set automatically.
2. you need to install the venv file in your Django project because you need to install all packages in this venv file.
3. after that, you need to enter the virtual env to install and run the project. you can run this command 'venv\scripts\activate.bat

this is my humble opinion. thanks.