Salem

Hi.

I have some problems feeding pumpkin flesh to my pythons. Do they still eat it?

no, cabbage and other pot plants

You can use berries if that's worthwhile.

They also eat the leaves of myrtle oaks, but thats no option anymore. They used to respawn in less than 24h, now the respawn time is somewhere between 2 weeks and never.

Go with the cabbage. It's easy to raise cabbages purity, at least until you have your worms upgraded and can start bringing out high purity radishes and what not. Cabbage is also better since you can get many leaves from a single head.