How to watch for a variable change in python without dunder setattr or pdb

Question

There is large python project where one attribute of one class just have wrong value in some place.

It should be sqlalchemy.orm.attributes.InstrumentedAttribute, but

Answer 1

def __setattr__(self, name, value):
    if name=="xxx":
       util.output_stack('xxxxx')
    super(XXX, self).__setattr__(name, value)

This sample code helped me.