How long until I need to worry?

[Kururu]

So my 3-year-old ball python hasn't eaten in about 3 months now and he has only lost 30-40 grams (currently he's 1,215 grams). I know it's nothing to be worried about now but how long would you be okay with your ball python not eating? Should I start worrying if he doesn't eat within the next 2 months? Or should I not worry at all how long he doesn't eat for (even if it's 6+ months) as long as he isn't losing significant weight?

Also, his weight bounces between 1,215 and 1,225 grams. Now at first I thought he was drinking and urinating but he actually hasn't done ANYTHING in terms of waste for the 3 months he hasn't eaten for. And I see him drink often.