You can get the pages for one given student number from the SQLite databases. See attached perl script as an example — it uses the subjectpageForStudent and subjectpageForStudentA SQL queries as defined in source:AMC-perl/AMC/DataModule/layout.pm.
To get the page where a particular question/answer box is located, look at the layout_box database (from the data/layout.sqlite SQLite file) to get the page inside the student's question sheet (and then layout_page database to get the corresponding page from the subject PDF file with all students' sheets if you need it).

I forgot the script…

Thanks! That gives me a place to start. This will tie my code more directly to AMC, so I guess I need to think about that ...
I have been splitting the pdf in a separate directory, but it makes sense to do it in the project directory also.

You can also force all subjects to have the same number of pages, calling one or more \clearpage at the end of each student copy if necessary (as does \AMCcleardoublepage).

Ok,
Thanks.

I guess I missed that command. I thought it was for answer sheets only. However, it is not clear it will entirely fix my problem. If the difference between sheets is only one page, it might work, but what happens when the short exam ends on an even page and some other exam needs an extra page? It seems I would still need to know the number of pages for each exam. Am I looking at this incorrectly?

I suggested to define another command, like AMCcleardoublepage, (say \AMCcompleteTo{n}), that adds blank pages at the end of short students sheets to give all students the same number n of pages. However, n has to be fixed manuallyat the beginning, depending on the subject (you can increase it if necessary after a first try). Perhaps this is posible to run LaTeX once to get the right value of n, and then run LaTeX again using this value as a parameter of \AMCcompleteTo, but this is more complicated to implement.

Ah. Got it. However, I prefer to figure out how to split based on the number of pages of the exam, rather than adding extra pages to some exams and not others. Thank you for your script. Its a good starting point.

I am handicapped a little by the fact that all of my scripts are in python and I don't really know perl, but maybe its time I did...

The perl script I provided uses only two SQL queries that you can find in the layout.pm perl file. You can use python to access the SQLite databases if you prefer.

Thank you.

I know this is delayed, but I appreciate the help. I was able to figure out how to use sqlite databases in python, and easily modified my script.