More of an open question to knowledgeable people or Google. I hope it's okay with you:
Which Python version is running on which deep learning container is unclear to me.
Take as an example europe-docker.pkg.dev/vertex-ai/training/tf-gpu.2-9:latest. It is not explicitly stated that Python 3.7 is being used (for others, it is occasionally stated). It would be beneficial to make it clear. Additionally, Python 3.7 will soon stop receiving security updates; at that point, supporting Python 3.8 will be more prudent. Perhaps in addition, how would I find out in advance when Google starts upgrading its base containers to the newest version of Python?