How to recognize stress

[Mrr]

Thank you! I was a bit worried today, after a different group (who believes that ball pythons should never be handled, outside of cage cleaning) told me that I was likely stressing him out. I work in the behaviour field (albeit with people), so I thought that I would inquire a bit more about this first. From my observations, he didn't seem like he was stressed, but I'm also still learning about reptile behaviour. I've only had this guy since September, and he was quite jumpy and would be ready to strike at any movement for the first few weeks, so I'm really happy that he seems to be comfortable enough to occasionally come hang out with me. I just wanted to make sure that I wasn't missing any potential stress signals.

So I guess my follow up question is... Is handling them really that bad? As I said, the Facebook group that I'm on ("Ball Python people") states that ANY handling is too stressful for the snake, and should be avoided. However my other ball python, a 3 year old pied female that I've had since a hatchling, is so calm and seems to love to explore when she's feeling up to coming out. If she ever seems stressed or is trying to hide, I immediately put her back in her tub. She has never once in 3 years hissed, attempted to strike, or refused food.. So I'd like to think that my occasional handling (1-2x a week maybe) isn't hurting them, right?