There are only a few packages that ship a binary only binary approach in the Python corner. And if so the ecosystem is more complex. That's not the case for keepkey.
This seems quite odd to me. If a Python module contains a corresponding application that is frequently used directly, I would expect this to be installed in its own package, named like the application, and not in a pyhon3-modulename package. If the corresponding module is rarely, if ever used, it's probably better to not produce a python3-modulename package at all, and simply put the module into /usr/share/modulename - this is described in the packaging policy: [1] In fact, I can't find any guidance on combined Python module+application packages (except for the mentioned case of private modules) in the Debian Python Policy. If there is any, I'd be very interested as well. [1] https://www.debian.org/doc/packaging-manuals/python-policy/#programs-shipping-private-modules
