Python bindings modernization: nanobind migration plan and Phase 1 infrastructure

[Copilot]

Establishes migration path from 994 lines of custom C extension generator to nanobind. Research shows nanobind (by pybind11's author) delivers 4-10× performance gains, 5× smaller binaries, and zero-copy NumPy integration—critical for real-time audio DSP.

Changes

Research & Decision (PYTHON_BINDINGS_MIGRATION_GUIDE.md, PYTHON_BINDINGS_SUMMARY.md)

• nanobind selected over pybind11: Superior performance (10× lower overhead), smaller binaries, modern C++17, excellent NumPy integration
• Complete 5-phase migration plan (14-20 days): Infrastructure → PoC → Core Types → Objects → Validation
• Detailed implementation steps with C++ wrapper patterns, nanobind binding examples, test strategies

Phase 1: Build Infrastructure

• vcpkg.json: Added nanobind dependency
• meson_options.txt: New nanobind feature flag (auto-detect)
• python/nanobind_bindings/: New directory with meson.build, C++ wrapper template, module docs
• python/tests/test_nanobind.py: Test framework (10 test stubs)
• Graceful fallback when nanobind unavailable—coexists with existing C extension

Migration Strategy

# Current: Custom generator parses aubio.h → generates C extension
gen_external.py + gen_code.py (994 lines) → gen-onset.c, gen-pitch.c, etc.

# Target: Modern C++ bindings with nanobind
aubio_cpp::Onset wrapper → nanobind bindings → Python with type hints

Incremental migration preserves API compatibility. Both binding systems coexist until Phase 5.

Next: Phase 2 (Proof of Concept)

Implement fvec/cvec bindings to validate approach and benchmark performance claims.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• www.fftw.org
  • Triggering command: curl --fail --retry 3 -L REDACTED --create-dirs --output fftw-3.3.10.tar.gz.3939.part -H User-Agent: vcpkg/2025-10-16-71538f2694db93da4668782d094768ba74c45991 (curl) (dns block)
  • Triggering command: curl --fail --retry 3 -L REDACTED --create-dirs --output fftw-3.3.10.tar.gz.4540.part -H User-Agent: vcpkg/2025-10-16-71538f2694db93da4668782d094768ba74c45991 (curl) (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

review the optimisation priorities and begin working on modernisation of the python bindings.

I want to use either pybind11 or nanobind - establish which is the best option using the latest information available on the internet.

begin this piece of work by collecting and documenting all essential steps and stages into a python bindings migration guide, and then begin implementing once the steps and guides are fully completed

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