[Python-Dev] [Python-3000] RELEASED Python 3.0 final (original) (raw)

Brett Cannon brett at python.org
Thu Dec 4 23:03:52 CET 2008

On Thu, Dec 4, 2008 at 13:07, Nick Coghlan <ncoghlan at gmail.com> wrote:

Terry Reedy wrote:

and this could give some people a mis-impression, most likely negative, as to the magnitude and nature of the change. Most of the code I am now writing would, I believe, run with 2.5 except for print(..., file=xxx). And I know that there was concern for backward compatibility to the point that some changes were rejected (renaming builtins) or delayed (deleting duplicate test asserts) for that reason. So I would soften the statements to "... version of the language that is partially incompatible with... " and "were made without being bound by backward compatibility," I would agree with Terry - while there are backwards incompatibilities, they aren't gratuitous. Then again, Guido does seem to want to discourage people from trying to target the common subset of the two languages instead of using 2to3 as a compilation step from the python3 version.

It makes sense if your code would have required jumping through hoops to keep the base use-case. But if the only major difference is something easily covered by a future statement (think print_function or unicode_literals, I believe although that future statement is not documented anywhere according to Google), then I honestly think it's okay to try to target the subset.

-Brett

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