If you would like to use HDF5.jl, I might be able to help. However, the error you are seeing comes from the cis Python package.
I’m not sure why you would be using Python 2.7, but that is far outside of support.
I suggest downloading miniforge, creating an environment with cis, and then trying to load this with Python 3. If you have problems there, contact the CIS authors:
Once you have working Python 3 code, please show us what that is.