C API: No longer exit Python in Py_InitializeFromConfig() #158080

When PEP 587 "Python Initialization Configuration" (PyConfig C API) has been implemented, the code to initialize Python was scattered in many places, and it was a tedious task to move all options to the new PyConfig structure.

The PyConfig structure has a wart that I always hated: Py_InitializeFromConfig() can fail with an exit code. It requires the caller to handle this special case: "Python wants to exit".

I propose moving the processing of command line options which want to exit Python: process these options in Py_RunMain() instead. So Py_InitializeFromConfig() can no longer exit with an "exit status": PyStatus_IsExit(status) is always false.

Py_RunMain() return value is an exit code, so it's more natural to process the command line options there.

PEP 741 "Python Configuration C API" just inherited its "exit status" from PyConfig in PyInitConfig. If we fix Py_InitializeFromConfig(), Py_InitializeFromInitConfig() will be fixed as well.

Linked PRs

• gh-158080: Py_InitializeFromConfig() no longer exits Python #158085