During my investigations related to low-level function/method classes, I came across the "instance method" class. There is a C API for it: https://docs.python.org/3.7/c-api/method.html However, it's not used/exposed anywhere in CPython, except as _testcapi.instancemethod (for testing its functionality) This class was discussed at https://mail.python.org/pipermail/python-3000/2007-December/011456.html and implemented in https://bugs.python.org/issue1587 Reading that old thread, there are use cases presented related to classic classes, wrapping Kogut (http://kokogut.sourceforge.net/kogut.html) objects and Pyrex. But classic classes no longer exist and the latter two use cases aren't actually needed if you read the thread to the end. So there are no surviving use cases from that thread. Does anybody know actual use cases or any code in the wild using it? To me, the fact that it's only exposed in the C API is a good sign that it's not really useful. So, should we deprecate the instance method class? Jeroen.