> Proposed patch renames METH_FASTCALL to METH_FASTCALL|METH_KEYWORDS
> and makes bare METH_FASTCALL be used for functions with
> positional-only parameters. This eliminates small cost that
> these functions pay for handling empty keywords: calling
> _PyStack_UnpackDict() and _PyArg_NoStackKeywords(),
> passing kwnames. This also can slightly reduce stack
> consumption.
+1 for all the reasons listed. These are very reasonable specializations. The empty keyword checks are really irritating for fine-grained functions.