I need help to know if it is possible and how it is done,Control the constraints in assembly through expressions as it exists in part mode for the featuresconstraints through expression as it exists for features
Yes. Check the article Assembly Driven Constraints
You can also define the different arrangements and make assembly constraints arrangement specific where expressions can also be used.
This is not what I intend, I need to suppress or unpress constraints controlled by expressions.
I don't believe that's currently possible.