[greggyb]

Pythons 4, 5, 6..., N will feasibly exist in the future. Why should Python 2 forever retain the executable name 'python'?

[michaelmrose]

Eventually logically python 2 will be little used enough to be dropped and there may not be a python4 any time in the foreseeable future so perhaps you are just borrowing trouble.

[marvy]

If Py4 is compatible with Py3, why bump the version number? If not, you better be careful which one you get!