I propose to deprecate 42 private functions of the C API:

• _PyArg_ParseTupleAndKeywordsFast(): see[C API] Removed private _PyArg_Parser API has no replacement in Python 3.13 #112136
• _PyCode_CheckLineNumber()
• _PyDict_GetItem_KnownHash()
• _PyDict_NewPresized(): see[C API] Add PyDict_NewPresized() function #139772
• _PyErr_ChainExceptions1(): see_PyErr_ChainExceptions1 no longer avallable to extension modules in Python 3.13 alpha headers #116809
• _PyEval_SliceIndex()
• _PyEval_SliceIndexNotNone()
• _PyFrame_IsEntryFrame()
• _PyInterpreterState_GetEvalFrameFunc(),_PyInterpreterState_SetEvalFrameFunc(),_PyEval_EvalFrameDefault(): PEP 523
• _PyInterpreterState_RequireIDRef()
• _PyInterpreterState_RequiresIDRef()
• _PyLong_AsByteArray(): usePyLong_AsNativeBytes()
• _PyLong_Copy()
• _PyLong_FromByteArray(): usePyLong_FromNativeBytes()
• _PyLong_GCD(): call Pythonmath.gcd() function
• _PyLong_NumBits(): call Pythonint.bit_length() method
• _PyObject_CallMethodId(): usePyObject_CallMethod()
• _PyObject_Dump(): see[C API] Promote _PyObject_Dump() to a public function #141070
• _PyObject_FunctionStr()
• _PyObject_GetAttrId(): usePyObject_GetAttr()
• _PyObject_GetDictPtr(): see[C API] Add PyObject_GetDict() function #139852
• _PySlice_FromIndices(): usePySlice_New()
• _PySlice_GetLongIndices()
• _PyStack_AsDict()
• _PyThread_CurrentFrames(): call Pythonsys._current_frames() function
• _PyType_Lookup(),_PyType_LookupRef(): see[C API] Add PyType_Lookup() function #139847
• _PyType_Name(): usePyType_GetName()
• _PyUnicode_FromId(): usePyUnicode_FromString() and cache the result; see the olddiscussion (2023)
• _PyWeakref_ClearRef()
• _Py_BreakPoint()
• _Py_GetGlobalRefTotal(),_Py_GetLegacyRefTotal(),_PyInterpreterState_GetRefTotal(): call Pythonsys.gettotalrefcount() function
• _Py_HashDouble(): seedecision issue #2 anddecision issue #10
• _Py_NewReference(),_Py_NewReferenceNoTotal(),_Py_ForgetReference(),_Py_ResurrectReference(): seeold issue
• _Py_ReachedRecursionLimitWithMargin()

If one of these functions is used, users should request a public C API replacing the private function.

I propose tonot schedule the removal of these functions for now.