[crabbone]

The answer is "sometimes".

Python can be relatively easily embedded in a C program and its source code can be compiled to C. The problems come from Python modules that are built to use shared libraries. It's not impossible to solve, but it means that you'd have to find the source code for those modules and recompile them to link statically with those libraries. This could be quite an undertaking, and is probably not worth it, unless you want to learn more about build systems and build tools in general.

Finally, in some cases it's impossible due to the licensing. I.e. you may have a Python module that relies on a shared library with license that prohibits redistribution. In that case it's not a technical, but a legal problem. This, however, isn't unique to Python, and you'd face similar issues no matter the language you chose to use.

Re' Docker: in most cases this is not a solution to making command-line interfaces. I actually struggle to think in what case it is. You'd have to write a program with the command-line interface and then put it in the image for Docker to create a container from (which will usually make it very inconvenient to use due to the Docker containers by default running such programs in separate filesystem, user and network interfaces.) This would make things like user identity, user's data and, well, obviously, network hard to access for the program while gaining you noting of substance.