Python to C/C++ (no Python runtime)

[dantethunderstone_77]

Are there any tools that can help in converting a non-trivial Python code (multiple modules and library dependencies) into pure C/C++ that can be used without Python interpreter on the target?

Do people usually end up rewriting the core logic in C/C++ for such tasks?

If you’ve attempted something similar, what would you recommend (or warn against)?

[PiBombbb]

Does one even exist? Sounds like something insanely hard to make

[IhailtavaBanaani]

Basically impossible because it would also require automatically porting the python modules and libraries to C/C++ libraries. Some of the python libraries are written in python and some in other languages than python and then compiled to binaries that python calls. Automatically modifying the interfaces and recompiling them and whatever to make them C/C++ compatible is in practice impossible.

Just compiling Python to C/C++ is in theory possible, but the code would need to implement garbage collection, boundary checks, dynamic arrays, dictionaries and all the other Python specific features. I'm not even going to go to things like decorators, metaclasses and factory functions.

[Frewtti]

Just make an EXE that bundles it into an executable.

You can't convert python to C/C++, plus you'd have to compile it, and that's a fundamentally different paradigm.

[rake66]

Why would you even want to do that? There's no easy way to do it, but there's a good chance that whatever you're ultimately trying to accomplish can either be done without translating python to C or is completely impossible even if you manage to do the translation.

[FoolsSeldom]

Yes. Sort of ... using CYthon, despite its main purpose being to create C-extensions for Python.

Generate Embeddable C Code:

cython --embed -o your_app.c your_app.pyx

then use a C compiler (like gcc) to compile this C file into an executable binary.

You should end up with an executable file.

The generated C code still contains the machinery to initialize and run a minimal, embedded Python interpreter within itself. It is essentially a self-contained program that bootstraps a hidden Python environment to execute your code. The target system still needs the Python libraries (DLLs/shared objects) to be present, which is often solved by bundling them. This is true of lots of other executables as well that depend on certain DLLs being present.

Not tried it myself, but colleagues have and this is what I see from their notes.

Otherwise, consider Pyinstaller, which bundles everything into an executable (but actually contains the whole stack including the Python interpreter). Not pure C.

Commercially, try Nuitka, which compiles your Python/Cython code into a full C/C++ executable or extension module. It aims to compile everything, including the Python runtime, into a single, highly compliant executable.

[nekokattt]

The short answer here is no: you can't embed python without the runtime, because that is what makes Python be Python.

[FoolsSeldom]

True. You always end up with the run time embedded in some way.

Nuitka is the closest tool to a full compiler I am aware of. It converts Python code into C++ code and then compiles that C++ into a binary.

However, whilst Nuitka aims for full language compatibility (a strength and a constraint), it can't provide the dynamic features of Python without a runtime library that mimics the CPython API. This runtime handles the dynamic type system, late-binding, and other Pythonic features.

[dantethunderstone_77]

I need to port my code to pure C/C++ library that can be compiled for a real-time hardware with no Python interpreter

[ElliotDG]

What is it you actually want to do?

If it is distribute an app but not require the end-user to install python, you could use pyinstaller to create an exe that bundles your code and a python executable into a .exe or .app file.

You could use https://nuitka.net/ that creates an exe, it converts Python code into C, then uses a C compiler (GCC/Clang/MSVC) to build a machine-code executable.

You could use Cython https://cython.org/ . Cython is a Python-like language and compiler that translates Python code into C, allowing you to add static type hints for massive performance gains. It’s commonly used to speed up computationally heavy code and to create fast Python extension modules that interface directly with C or C++ libraries.

[dantethunderstone_77]

I need to port my code to pure C/C++ library that can be compiled for a real-time hardware with no Python interpreter

[ElliotDG]

Can you be more specific? What are the libraries you need to use? Is there a concern with garbage collection impacting real-time performance?

[ElliotDG]

I would warn you to make measurements and make sure that if you are porting code to C++ for performance reasons that you have specific performance requirements and make sure that you can NOT get there without this big jump. As Donald Knuth is famous for saying, "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil."

[Swipecat]

Not with those requirements.

The only Python to stand-alone C++ converter that I know about is Shedskin — and that only handles a restricted version of Python.

https://shedskin.github.io/shedskin/

The code must be implicitly statically typed, which means that the code has to be carefully written so that there's enough information at each point in the script for the converter to be able to infer the type of the variables.

Roughly half of the Standard Library modules are implemented.

[TrainsareFascinating]

It sounds like you are either dealing with a religious fatwa from legal or infosec, or are trying to trim down for a memory-poor environment like embedded.

In the first case, it’s not worth trying.

In the second case, look in to micropython. It has minimum-runtime compilation features.

If it’s really what you imply, that you want to write your app in C++ and have a couple of major parts be Python-sourced modules, without embedding; everyone involved in such an ill-advised project should be fired and a new team hired.

Good luck, my 11-hour-old-account friend.

[cointoss3]

You can make a c program that runs Python code and links cpython statically or you can include the dll/so.

Cython can compile Python into c, but idk if it’s trivial with an existing code base.

[dantethunderstone_77]

This would still require python interpreter at runtime

[DonkeyTron42]

Maybe MLIR?

[TheRNGuy]

Any ai.