Address Matching Conditional on value of another column

[konsbn]

I have datasets like this
Dataset A

first_name	last_name	address	change_add
john	smith	PO BOX 123	1
adam	kay	23 MAGNOLIA DR	0
boris	becker	56 RYDE PARK	0

Dataset B

first_name	last_name	address
john	smith	JUPITER AVENUE
adam	kay	23 MAGNOLIA DR
boris	becker	56 RYDE PARK

Now I want to match these two tables. I'll compare them on first_name , last_name and address . However in case of john smith the change_add flag being 1 implies that he has changed his address in that case even different address should be matched.
I am unable to figure out a way how to do this using the CompareBaseClass please help me solve this problem. Thanks

[aflaxman]

I don't know how to solve this problem, but I wanted to see how my new simulated data might help me try it out. Here is a colab notebook that tries it out.