python 3.x - pip package "pillow" is installed but not working

Question

This is an error message when I executed 'python3 manage.py makemigrations'

SystemCheckError: System check identified some issues:
ERRORS:
main.Room.photo: (fields.E210) Cannot use ImageField because Pillow is not installed.
    HINT: Get Pillow at https://pypi.org/project/Pillow/ or run command "python -m pip install Pillow".

But I installed Pillow. When I typed pip list, there is Pillow 8.1.0.

Why Pillow is not working?

pip version : 20.3.3

django version : 3.1.5

python3 version : 3.7.3

`pillow version : 8.1.0``

I have done :

1. PYTHONPATH setting /usr/local/lib/python3.9/site-packages
2. pip uninstall Pillow & pip install Pillow

question from:https://stackoverflow.com/questions/65651149/pip-package-pillow-is-installed-but-not-working

Answer 1

Waitting for answers