On 2026-05-11, Lawrence D’Oliveiro <[email protected]> wrote: > On Sun, 10 May 2026 21:01:00 -0700, Paul Rubin wrote: >> Lawrence D’Oliveiro <[email protected]> writes: >>> For those times when a simple “None” marker element is not >>> sufficient, this will be very convenient. >> >> object() has always worked for me. > > I have done the same, on a few occasions. That’s been a common idiom > among Python programmers since practically forever. The PEP discusses > why this is less than an optimal solution: less-than-explanatory > diagnostics, and difficulty with type signatures for static typing.
I've always used (and seen) "SENTINEL = []"... > Also, an “is” comparison fails if you should (inadvertently or > otherwise) make a copy of your sentinel object. That doesn't seem terribly likely to happen by accident though. -- https://mail.python.org/mailman3//lists/python-list.python.org
