How to pass boolean expression through Django to db?

Question

Django

There is a model A with fields b, c, d (let everything be text fields).
There is an action in the view that takes a logical expression as input, for example:

(b = 'test1' and c = 'test2') or d = 'test3'

The logical expression can be anything. How to filter model A by a given expression?
You can just substitute it in raw SQL code, but then it's an open SQL injection.

Answer 1

1) validate what was sent to you
2) make a constructor for DNF or CNF