pyapi-compat-if

Implements a compatibilty interface allowing C++ code to call Python without being tied to a specific Python version

Use Case

Python extension modules are fairly tightly bound to a specific Python interpreter and version. This is fine in many cases, but causes an issue when a native library wants to use Python without being tightly coupled to a specific Python interp/version.

The implementation of pyapi-compat-if has two pieces:

• A C++ pure-virtual class API that roughly follows the CPython API. This API is independent of a Python interpreter and version.
• A Python extension that is tightly bound to a specific interp/version. The interp/version-specific extension provides an implementation of the C++ API.

Use Model

The core C++ API provides a mechanism to discover the Python interpreter and load the pyapi-compat-if extension module into it. When the extension is loaded, it registers the interp/version-specific version of the C++ API implementation. The C++ application can now evaluate code in the interpreter.