Traits are saved in a data structure named trait_dict.
Which is not necessarily static. E.g.
_neronero's Fran pack tried to play with adding dynamically created traits; and I had no end of trouble in Bonanza because I added a modified form of Trait King and regenerated the whole trait dictionary. So
when you create these lists can matter, and a girl can perchance have traits outside of that list.
Edit: Also, 0.15b - which is
still the main release - has some traits (Godless and the four you get for losing a girl's virginity) outside of that dictionary.
You can create a list of of the keys of this dict and compare text to text in a cap insensitive manner.
Which is exactly what I suggested earlier.
No real need to create that list, either, because in the worst case it might get changed due to mods etc afterwards. And the performance increase is marginal. So you can just use trait_dict.keys() directly.
Note that Ren'Py still uses Python 2, where lowercase conversion is somewhat iffy if you have 'exotic' characters in your text, like Greek or
ß.
And then you can fix the capitalization, WhAtEveR iT Is, on a case by case basis.
Uh, the whole point of this exercise is
not to have to do that, right?
You could also put the whole thing into a try-catch block, so the game won't do a 'hard' crash on mistakes.
You're right that it's not rocket science, but there are several nuances here that can be solved now, instead of ignored and then reinvented by the unlucky souls who try the trainer on e.g. Trait King 0.2 if that ever comes out.