I know this is an older post but I think your script could help with something similar I was trying to do.
I want to be able to use Data Driven Pages to give me a list of features from another layer (point) within each page.
Basically, I have a GRID polygon layer with a field called PAGE. PAGE is used for DDP with a range of 1-184.
I also have a point layer called TRAFFIC SIGNS that has a field with unique FACILITY_ID numbers that I use for inventory purposes.
For each PAGE I want to select all the TRAFFIC SIGNS within the page and write out each traffic sign's FACILITY_ID to a text file.
I am new to Python so bare with me and thanks for any advice ahead of time!