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Hmm, it seems our notes crossed paths, sorry. On Tue, Oct 26, 2021 at 2:12 PM Chris Angelico <rosuav@gmail.com> wrote:
The trouble with sentinel values is that you always need another one. Sooner or later, you're going to need to talk about the _missing object, and you'll need to distinguish it from the absence of an object.
If there is a way to say "don't pass this argument", it would have to be some kind of syntactic token.
I don't think that's true. even now, folks can misuse None, and True and False in all sorts of ways, but if a singleton is well documented to mean "missing argument" then anyone who uses it some other way gets what they deserve. The reason None can't be counted on to mean MISSING is that is, in fact, used in other ways already. -CHB -- Christopher Barker, PhD (Chris) Python Language Consulting - Teaching - Scientific Software Development - Desktop GUI and Web Development - wxPython, numpy, scipy, Cython