Using standalone Django project
I would like to split my Django project into 2 projects :
one responsible for updating the database (the information is gathered automatically from the outside, no user input).
one reponsible for exposing the database to the users.
I would say that the second one is more like the classical Django project. And I mostly wonder how I will handle the first one. There are 2 issues that concern me :
1) Is it possible to have 2 different projects using the same database ? If so, do I need to have the same models in both project ?
2) Is it possible to run Django in "minimal mode" ? I mean having just the necessary to work with the database but not the HTTP server part : routing and so on (for security reasons, I don't want my updating project to be accessible through HTTP).
I have in mind to run each project on a separate server. Therefore I cannot just create 2 apps in the same Django project.
It looks like you have a lot of reading to do, please start here.
What you're describing can be done using apps in a single django installation. You'll have an app responsible for the first part you described, and another app that is exposed via urls for the second part.
Accessibility through API is defined by you. If you don't define a url for something it will not be accessible.