Terry, if the default for stdlib __str__ for stdlib enums changes to module.enum_member_name are you okay with changing the custome __str__ you are using for the EventType enum at the moment?

I think it would be better to restore the default __str__: __str__ = str.__str__ (it looks not safe to change __str__ of str subclass) and change self.type in Event.__repr__() to getattr(self.type, 'name', self.type).

Serhiy is indeed the one to answer the question as he is the tkinter maintainer. As a user, my concern is with breaking existing code and the possible uses of str(). EventTypes are used for the event.type attributes of events passed to event handlers. If a handler can be triggered by more that one type of event and the handler cares which, one condition would be event.type == EventType.Sometype, for which the string representations matter not. (I would probably define `Ev = tk.EventType if doing much of this.)

Conditions like str(event.type) == 'KeyPress' would break, and I don't consider their existence to be out of the question, as we use strings to bind the event. Before this issue, I might have done this. (I had to experiment to be sure of how to use the enum 'properly'.) The NMT tkinter reference does not mention EventType. And, of course, the mapping and code that uses the names predates enums. For output to a user, the module prefix might be noisy.

Terry, fair enough.

Serhiy, there are no issues with a custom __str__ on an Enum class, even when it is subclassing str. The question is whether we want str(EventType.KeyPress) to be "KeyPress" or "2".

As Serhiy explained on Python Dev: The issue with having a custom __str__ on a string subclass is that

str(subclassed_thing) != subclassed_thing

and it should be.

I am also the one who introduced EventType. And I now think that maybe making __str__ returning a name instead of value was mistake. The main reason of defining __str__ was to use it in Event.__repr__().

But this is a different issue (I am working on it, the hard part is writing tests). This issue is about trailing commas which convert values into tuples. Thank you Ethan for catching this! Let to fix it.

Would be nice to add a NEWS entry. This was a serious bug.

Adding news entry.

I cannot think of any use for the arbitrary numbers, whether string or int, added by tkinter to the tk strings.

Serhiy, thank you for the explanation on Python-Dev about str() vs __str__. I'm fixing StrEnum now to use str.__str__.

Thanks @ethanfurman for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8.
🐍🍒⛏🤖

Thanks @ethanfurman for the PR 🌮🎉.. I'm working now to backport this PR to: 3.9.
🐍🍒⛏🤖

GH-22366 is a backport of this pull request to the 3.8 branch.

GH-22367 is a backport of this pull request to the 3.9 branch.