> Did I mention __index__ is an unfortunate name for the current trend for this method? Yes, but it's probably too late to change that now. Also, a fully precise name would be something like: __to_int_exact_iff_object_has_integer_nature__ :) > When you say "accept __index__" do you mean for use as indices, or for use as > values in the data structure itself? The latter, see Lib/test/test_buffer.py:2489 .