Terry Reedy wrote: > Guido van Rossum wrote: >> On Tue, Nov 3, 2009 at 9:37 AM, "Martin v. Löwis" <mar...@v.loewis.de> >> wrote: >>> (and no, adding things like nonlocal to 2.7 doesn't making porting of >>> a real application or library any easier, since the existing application >>> or library simply doesn't use that keyword. >> >> Agreed. >> >>> In fact, no change to 2.x >>> can reasonably simplify porting - only changes to 3.x might - except >>> for changes to 2to3, which can simplify porting a lot. But 2to3 should >>> be run under 3.x, IMO.) >> >> Disagreed. Better "-3" warnings could make porting easier. (Not just >> more warnings -- "better" might mean fewer false positives for >> warnings already issued.) > > There is also Eric Smith's list to consider: PEP3118 new buffer > protocol, short float repr, and maybe io.
The pure Python io module was already backported for the 2.6 release [1], as was the C API aspect of PEP 3118 [2]. Short float repr has since been backported for 2.7, as has the C accelerated io module implementation and the Python API (memoryview) aspect of PEP 3118. I believe those 3 features alone are more than enough justification to proceed with at least a 2.7 release (that is probably the point Eric was making in posting that list of features in the first place). As to how those backports can help with forward ports to Py3k, someone made the point elsewhere in the thread that testing/experimenting via 2to3 is a very C++ like development cycle - there is a long build time before you get to see the results of running a test. With features backported to 2.x, you can instead use more traditional version checks (or the interactive prompt) and get the usual quick feedback cycle via the 2.7 version, before submitting your code to the tender mercies of the 2to3 converter (or possibly avoid 2to3 altogether if the version checks turn out to suffice for a given use case). Cheers, Nick. [1] http://docs.python.org/whatsnew/2.6.html#pep-3116-new-i-o-library [2] http://docs.python.org/whatsnew/2.6.html#pep-3118-revised-buffer-protocol -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia --------------------------------------------------------------- _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
