As soon as your code touches the database (or a mock of it), it looses most of its re-usability. It suddenly becomes much harder to use it elsewhere. In most cases, the code is then tied to that particular framework (like Django, or Flask), and you cannot move it out into a separate independent module. This becomes a problem in large projects, and for example micro-service architectures.
It also mixes up the levels of abstraction. Getting and instantiating objects is mixed right (hard coupled) in with the code that uses them.
Comments
I agree entirely.
As soon as your code touches the database (or a mock of it), it looses most of its re-usability. It suddenly becomes much harder to use it elsewhere. In most cases, the code is then tied to that particular framework (like Django, or Flask), and you cannot move it out into a separate independent module. This becomes a problem in large projects, and for example micro-service architectures.
It also mixes up the levels of abstraction. Getting and instantiating objects is mixed right (hard coupled) in with the code that uses them.