Python idea - patron commission picker (Patreon)

It seems my Python switch has been flipped this morning! First it was a idea generator for times when I'm feeling art-blocked, now I have another in mind - a script that could award a commission to a random patron.

I'd done commission raffles before, until Patreon banned them. This script would be different, because it wouldn't be tied to specific tiers. Any patron could win, just by being a patron. BUT, the odds of winning might be improved by how long one has been a patron, and the total amount they've pledged in that time.

Any thoughts?