Macro __pyo3_pyinit 

#[doc(hidden)]
macro_rules! __pyo3_pyinit {
    ($symbol:literal, $def:path) => { ... };
}

Available on not (Py_3_15 and Py_GIL_DISABLED and Py_LIMITED_API).

Defines the PyInit_<name> entry point used by Python 3.14 and older.

This is wrapped in a macro_rules! so the proc-macro backend can emit a single version-agnostic invocation; the body only expands on Python 3.14 and older