Hi Piotr,
> ("mypackage" is module name which will be shipped in python3-mypackage
> binary package and "rpi" or "rpi-daemon" is binary package shipping the daemon)
> [...]
> if it's one file only (without private modules) you can install directly
> into /usr/bin/
The file rpi.py is a module of mypackage, not the binary of the
daemon. The binary will be installed in its own package that requires
python3-mypackage.
Bye
Simone