Revision 0b7c313851ca highlights an inconsistency in the test case at the top of the TestPredicates class. After removing isawaitable() in Issue 24400, there are now actually eighteen is* functions. The comment in the test case still says there are sixteen (from before the two iscoroutine* functions were added), and so does the documentation it references: ‘The sixteen functions whose names begin with “is” ’ <https://docs.python.org/3.5/library/inspect.html#types-and-members>. The quick fix is to change all the numbers to eighteen.

But maybe a better fix is to drop it all and rewrite the documentation to just say “The functions whose names begin with “is” are mainly provided . . .”.

New changeset a5c6eaa7d733 by Yury Selivanov in branch '3.5':
Issue #24541: Update comment in test_inspect.test_eightteen
https://hg.python.org/cpython/rev/a5c6eaa7d733

This has already been fix (see issue24400).  I've also updated the comment (16 -> 18).  Let's keep the test as is.

Okay but what about the documentation? It still claims sixteen.

# This test is here for remember you to update Doc/library/inspect.rst

New changeset bd45435fd081 by Yury Selivanov in branch '3.5':
Issue #24541: Drop test_inspect.test_eightteen unittest; update docs
https://hg.python.org/cpython/rev/bd45435fd081

Thanks for pushing this Martin. I didn't notice that you suggested to update inspect.rst as well. And it does make sense to just remove the number of is* functions from the docs (and after that we don't need the unittest).