What should I do when I modify code after compose up

I have a Django app I composed it using docker-compose up but after that, I need to modify or update some files in my app what the best choice editing in real or my computer or go inside the docker container and using docker exec. because if I updated some file in my project on my computer I don’t have the dependencies as same as in inside docker container. on the other side if I want to edit or update file inside the container using terminal I don’t have the tools make me editing the app files

The answer depends on where these files come from. Are they stored in a volume? Or copied from the host on startup of the container?