This repository contains two wrappers for the [http://github.com/tmolteno/necpp nec2++] antenna simulation package:

• necpp/ contains a wrapper using SWIG of the C interface (Python module name: necpp).
• PyNEC/ contains a wrapper of the C++ interfaces (Python module name: PyNEC). The example/ directory furthermore contains some nicer, more readable Python wrappers that make toying around with NEC a less painful experience.

Both are based on Tim Molteno ([email protected])'s code with major cleanup by Bart Coppens.

pip install PyNEC necpp

Wheels are built with the Python stable ABI (abi3): a single wheel per platform covers CPython 3.11 – 3.14 and newer.

Free-threaded CPython (cp314t) is not covered by the stable ABI — install from the sdist there (a full-API build is produced automatically).

Every release pins the necpp_src git submodule to a specific necpp commit. Two places identify it:

• the GitHub release notes and PyNEC/CHANGES.md name the necpp_src commit for each release;

• the compiled extension embeds it as necpp_engine_sha=<commit> — verify any installed wheel with:

  strings "$(python -c 'import _PyNEC, pathlib; print(pathlib.Path(_PyNEC.__file__))')" | grep necpp_engine_sha

Uses uv for modern PEP 517 builds. Generating the wrappers requires SWIG >= 4.4.1 (4.5.1 recommended — older SWIG cannot emit stable-ABI-compatible code); installing from a release sdist needs no SWIG at all.

git clone --recursive https://github.com/tmolteno/python-necpp.git
cd python-necpp

# Build PyNEC
cd PyNEC && ./build.sh && uv build

# Build necpp
cd ../necpp && ./build.sh && uv build

The cleaner API should really be ported to C++, so the clean wrappers get automatically generated, and C++ can use the same cleaner interface. But for now, I'm happy with the Python wrapper :)