On Wed, 14 Nov 2018 11:03:49 +0100 Victor Stinner <vstinner at redhat.com> wrote: > > Oh, I should stop to promote my "CPython fork" idea. > > There is already an existing VM which is way faster than CPython but > its performances are limited by the current C API. The VM is called... > PyPy! > > The bet is that migrating to a new C API would make your C extension faster. Faster on PyPy... but potentially slower on CPython. That's what we (you :-)) need to investigate and solve. Those macros and inline functions are actually important for many use cases. For example in PyArrow we use PySequence_Fast_GET_ITEM() (*) and even PyType_HasFeature() (**) (to quickly check for multiple base types with a single fetch and comparison). (*) https://github.com/apache/arrow/blob/master/cpp/src/arrow/python/iterators.h#L39-L86 (**) https://github.com/apache/arrow/blob/master/cpp/src/arrow/python/helpers.cc#L266-L299 Regards Antoine.