ModuleNotFoundError: No module named 'athena_read'

[Gribouillis]

I think your problem is the status of the pyfiles directory:

• Is pyfiles just a directory containing Python modules that you want to import? In that case, it should not have an __init__.py file and it should be on the Python modules search path as @AdamHensley wrote above.
  
• Or is pyfiles a Python package containing submodules? In that case unimesh.py should have from . import athena_read instead of import athena_read
  

In the first case, there are various ways to insert the directory in sys.path. One of them is to add to your site-packages directory a file with the .pth extension containing the path to your directory, for example

# in file mypythondirs.pth
/home/raman/Pictures/MikiForRaman/pyfiles

If you are using your system Python interpreter, you can put that file in the directory printed by the command python -c "import site; print(site.getusersitepackages())". If not, you can store it in one of the directories printed by python -c "import site; print(site.getsitepackages())"