I think the interesting part is what is revealed about Python and the difference with something like Ruby.
Python is stable[0] and places a high degree of importance on backwards compatibility.
This behaviour is well documented (and called out for particular note). This reinforces that it is (a) official and (b) not a bug because it is the documented behaviour.
On the other hand Ruby (and most Ruby libraries) seem both less concerned with backwards compatibility, have less thorough documentation[1] but are more willing to change and improve.
There isn't a right and a wrong between these approaches although for most things I think I would prefer something between the two. I think I generally prefer Python in terms of syntax (Ruby is a bit too flexible with too many ways to do things for my taste) but I do wonder if Python will be left a little behind.
[0] Python 2/3 transition is a single big deliberate change.
[1] I have an open Rails issue that I don't know if is a bug or not because there isn't documentation that is sufficient to compare the behaviour with so it is a case of what feels right/wrong: https://github.com/rails/rails/issues/6659
I'm gonna disagree with you! Well, I actually agree about ruby libraries, but the ruby standard library is the proper comparison here, which in my experience manages backwards compatibility and documentation of edge cases rather nicely. The (many) changes to the language itself since 1.8 have nearly all happened in backwards-compatible ways. So maybe the ruby community has a more flexible attitude (I've honestly never used enough external python libraries to have a good comparison point), but I don't think it's fair to say that the language itself is.
Python is stable[0] and places a high degree of importance on backwards compatibility.
This behaviour is well documented (and called out for particular note). This reinforces that it is (a) official and (b) not a bug because it is the documented behaviour.
On the other hand Ruby (and most Ruby libraries) seem both less concerned with backwards compatibility, have less thorough documentation[1] but are more willing to change and improve.
There isn't a right and a wrong between these approaches although for most things I think I would prefer something between the two. I think I generally prefer Python in terms of syntax (Ruby is a bit too flexible with too many ways to do things for my taste) but I do wonder if Python will be left a little behind.
[0] Python 2/3 transition is a single big deliberate change.
[1] I have an open Rails issue that I don't know if is a bug or not because there isn't documentation that is sufficient to compare the behaviour with so it is a case of what feels right/wrong: https://github.com/rails/rails/issues/6659