Outputting crunchable list of HBonds from Pymol X-posted from the Main Stack Overflow because folks here are possibly more familiar with PyMol(?)

I have been trying to assess the strength of an interface I want to mutate using Pymol. What I am interested in is a list of contacts withing a specified interface (which I have calculated using the InterfaceResidues.py script from the PyMol wiki script library). My aim is to produce a bunch of mutants using the mutagenesis wizard and assess how the HBond network changes.

Actions>Find>Polar Contacts does the trick in visualising them, but doesn't output a file with numbers which I can then crunch to assess which mutations weaken my interface most. 
I have been trying the scripts list_contacts.py and list_hb.py from Prof. Robert Campbell of Queen's University at Kingston, but with limited success (nothing gets printed or written to the file).
The scripts can be found here http://pldserver1.biochem.queensu.ca/~rlc/work/pymol/

I am going to contact Prof. Campbell directly re: scripts but, in the meantime, and in case he's too busy to deal with a Pymol noob, does anyone have any ideas of what else I could try?

I am using Pymol 2.3.1 and Python 3.7.1
Thanks a lot to all who commented/replied, the author of the scripts provided a response. It was down to a syntax change in PyMol of which I wasn't aware that caused my selection to come up empty.