Design a new better C API for Python

This project is a fork of the development version of the future CPython 3.8. The intent is to experiment to implement the new C API described at:

https://pythoncapi.readthedocs.io/

Install dependencies on Fedora:

dnf install -y make gcc check

Build and run unit tests:

./configure --enable-shared --with-pydebug
make
cd capi_tests
make  # only test Py_NEWCAPI
# or to run the full test matrix: make testmatrix

If you want to help, look at TODO.rst.

The changes live in the pythoncapi branch.

New C API defines:

• Py_NEWCAPI_NO_MACRO: replace macros with function calls PyTuple_GET_SIZE() becomes PyTuple_Size()
• Py_NEWCAPI_NO_STRUCT: must not use PyObject.ob_refcnt or any other field of Python object structures; structures should hide their fields: compilation error.
• Py_NEWCAPI: new C API without borrowed references, without macro, without struct

Related defines:

• Py_NEWCAPI_BORROWED_REF: declare functions/macros using borrowed references -- enabled by Py_NEWCAPI_NO_MACRO and Py_NEWCAPI_NO_STRUCT, but not by Py_NEWCAPI.

See also:

• github.com/pythoncapi/cpython
• capi-sig mailing list