Bhack:

from PyInstaller.utils.hooks import is_module_satisfies, \
    collect_submodule



Thanks, I got it working with that hook. Two futher changes were also required:
i) I had to change the line in the hook:
datas = collect_data_files('tensorflow', excludes=data_excludes)

to:
datas = collect_data_files(‘tensorflow’)
as excludes dosn’t seem to be in the API (at least for versions I have Python: 3.8.3, Pyinstaller 3.6)
ii) I had to add the following import to my python file:
import tensorflow.python.keras.engine.base_layer_v1
Thanks a lot!
D.