[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-27 Thread Raymond Hettinger
Raymond Hettinger added the comment: > That being said, I believe (as the OP of issue 8743) > that the ABC collections should comply to the API of > the Python base collections. Sorry Horacio, but your beliefs don't trump Guido's intentional design decisions. He was the one who decided

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-27 Thread R. David Murray
R. David Murray added the comment: I suppose someone could propose a set of tests that an implementation of an ABC type should pass, to complement the stdlib type tests. There would probably be a lot of bikeshedding involved in such tests though, so I don't hold out great hope anything would

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-27 Thread R. David Murray
R. David Murray added the comment: For backward compatibility reasons, history will win. I'm not sure if documenting the additional restrictions of the concrete stdlib types in the ABC docs makes sense, either, since the ABCs are intentionally the minimal requirements for a concrete type to

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-27 Thread Horacio Hoyos
Horacio Hoyos added the comment: Although I agree that some design decisions forge a language and sometimes these historical developments win over sounder or more "logical" arguments. That being said, I believe (as the OP of issue 8743) that the ABC collections should comply to the API of the

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-26 Thread Raymond Hettinger
Raymond Hettinger added the comment: > I would expect the and operation between my set implementation > and a string to fail with a TypeError, given that string is > not an instance of Set. However, the error is not raised ... Odd as it may seem, this isn't a bug; rather it was a deliberate

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-23 Thread Serhiy Storchaka
Changes by Serhiy Storchaka : -- assignee: -> rhettinger ___ Python tracker ___

[issue30146] Difference in behavior between set() and collections.abc.MutableSet() derived objects

2017-04-23 Thread Ned Deily
Ned Deily added the comment: OK, thanks for supplying a concrete example. From it, it's clear that it has nothing specific to do with Python on macOS. Adding Raymond as maintainer of sets. -- components: -macOS nosy: +rhettinger -ronaldoussoren title: Fix for issue 8743 not