I'm currently facing some challenges while trying to package a Python library that relies on a small C component, which needs to be compiled into a shared object during installation. I want to make sure that the installation process is smooth for users, but I'm not sure about the best approach to take. Here are my main concerns:
1. If I need to compile the C component on the user's machine, users who lack a proper C toolchain could run into installation errors.
2. On the other hand, if I build and ship wheels for various platforms (like Linux, macOS, and Windows), it adds extra complexity to my CI/CD process.
3. I also have to decide whether to use `cffi` or `ctypes` for wrapping, which impacts the build process's complexity.
I've also been considering a fallback where, if the compiled extension fails to load, the library could revert to a pure Python implementation. However, that approach would likely be less accurate and could introduce correctness issues.
I'm looking for advice on:
1. Is it now standard practice to ship prebuilt wheels for any library that includes C code?
2. Would it be acceptable to provide a simpler Python fallback if things go wrong, or should I just let users hit a hard error?
3. Which wrapper option is preferred: `cffi` or `ctypes`?
4. How much effort is typically required to set up multi-platform wheel builds when dealing with a small but critical C dependency?
Thanks in advance for your insights!
4 Answers
Definitely aim to build wheels at release time and upload them to your repository. It might seem daunting, but the effort is minimal in the long run. You just need to set it up initially.
I recommend looking into using GitHub Actions or similar CI tools for this; it makes automating the building process a lot smoother. Plus, it ensures you don’t have to do it manually each time.
It’s becoming pretty much standard to generate and provide precompiled wheels for major platforms, particularly when C code is involved. If your library is critical, not having these could frustrate users. Also, between `cffi` and `ctypes`, I’d advise `cffi`. It tends to result in less error-prone code and uses a syntax similar to your bindings.
If it fits your needs, consider exploring Rust with PyO3 for future expansions; it’s gaining traction for safely integrating native code with Python.
For your first release, I'd suggest keeping it straightforward. Just ship a source-only package with clear documentation explaining that users need a C compiler. If issues arise from users lacking the right tools, you can add wheels for popular platforms later.
As for the fallback option, I wouldn’t recommend it. If users run into silent issues with a less effective Python alternative, they could blame your library without knowing why. It's better to fail hard with a meaningful error message. For the wrapper, I’d go with `cffi`; it's easier for newer users while still being effective.
That makes total sense! I was debating whether to include a fallback, but you're right—it's better to be clear about failures. I guess starting with a straightforward source-only release is the way to go. Thanks for the advice!
Cffi it is! Keeping it simple in the beginning sounds ideal.
Have you checked out `cibuildwheel`? It simplifies the process of building wheels across different platforms and Python versions. Setting it up might take a bit upfront, but it'll make your life easier in the long run.
I hadn’t looked into it yet, but this sounds worth checking out, especially since I need to make a C wrapper for my project.
I always have trouble uploading wheels to the index. They keep rejecting it; I've gotten errors about platform compatibility.