>Python 3.x has decided that breaking changes in minor releases is fine. My favourite: string prefixes (eg s'foo', u'foo') were legal in 2.x, removed in 3.0, added back in 3.3.
Python 3.0 was very much not a minor release, so your example is invalid.
The general point that Python does breaking changes in minor releases stands, but they do typically go through a deprecation period first.
Python 3.0 was very much not a minor release, so your example is invalid.
The general point that Python does breaking changes in minor releases stands, but they do typically go through a deprecation period first.