Very kind ball python now bite me every time I took him out of cage

[Bogertophis]

I wouldn't leave that shed on him, personally- it only gets harder to remove. I know you're uncomfortable handling him, but maybe this is just the "exercise" (ie. learning experience) you both need. Snakes don't typically bite thru cloth bags, & what I'd suggest you do is slide him into an old pillow case (use a hook to guide him in if you need to), then zip-tie it shut. Sit for a while with him in the "bag" on your lap, & just let him relax & learn your scent & touch through the fabric. Pet him softly.

This is a good thing for just "taming" a snake, btw, without the shed issue- because snakes are less afraid when they can't see us looming over them, & they find out we're NOT grabbing them like a predator. They do learn, & so do we. It takes empathy to calm a snake down, & most do.

But he also needs help now to shed, so then thoroughly moisten the cloth bag- not dripping wet, just very damp- and let him rest a while in that to help soak the old skin loose. At least an hour- the longer you wait to help a snake, the longer they'll likely need to "soak".

Then once again hold him in the bag on your lap while you guide him thru your hands (by feel thru the cloth) & do this until you get all the old skin off. The moist cloth is mildly abrasive & will help a lot. It might take a while- even a couple tries after you check. And bear in mind that sometimes moist shed looks clear, so you think it's all off when actually it's not. So looks very closely, & repeat as necessary. This will help you both get re-acquainted. From the many times I've done this over the years, it really seems like most snakes start to realize we're actually good for a few things after all.

From what I can tell, the body weight looks okay. Bites are usually either fear or hunger.

I've seen some snakes belonging to others (& usually not handled enough) that once picked up, would proceed to try to eat the hand that was holding them.

Rosy boas are known for being docile, so ironically, this used to happen with one that a nature museum kept & handled for public programs. Needless to say, when the presenter gets chomped on, it doesn't much endear the snake to listeners. Having much more experience with snakes than their staff did, I could even spot when the bite was about to happen, & some other snakes will also do this, which is why I mention it.

The snake would never hiss or struggle- it seemed perfectly calm, but once held for a while, she would start to gently prod the hand with her nose. Hint- she was looking for the "head"! Then suddenly the bite would happen. Oops, didn't see that coming? IMO, such bites were a combination of not being fed enough AND not being handled enough. What you described (about your bite) in your first post sounded very similar??? So I think that with your snake, it's both hunger & not spending enough time with you to really associate your scent with anything other than prey delivery. So now you have "homework"- haha.