String keys is what Raymond requested and what looks sensible to me. A week ago, I committed test_idle/test_hyperparser.py and an incomplete test_autocomplete.py. So we can now, for this issue, at least partly follow our standard procedure of requiring tests with patches.

I want at least a test of is_in_subscript_string(self) added to test_hyperparser. cls.code will need another line (or an existing string bracketed and the string test altered) and a new test_is_in_subscript_string added. If you are working from an installation rather that a repository, and therefore cannot write/test an addition to the new file, say so.

The change to auto-complete is trickier. I would have to look the code versus to tests to decide what to do, if anything. I might decide to improve the autocomplete htest (human test, in repository AutoComplete.py and test_idle/htest.py) rather than the unittest.

In any case, we need a signed contributor agreement to accept patches.
https://www.python.org/psf/contrib
https://www.python.org/psf/contrib/contrib-form/