[Python-Dev] readd u'' literal support in 3.3? (original) (raw)

Tres Seaver tseaver at palladion.com
Wed Dec 14 17:33:32 CET 2011

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On 12/14/2011 04:15 AM, "Martin v. Löwis" wrote:

It's "pure" in being optimized for a world where you just stop using Python 2 one day, and start using 3 the next, without any crossover support. That's not true. 2to3 is well suited for supporting both 2 and 3 from the same code base, and reduces the number of compromises you have to make compared to an identical-source approach (more dramatically so if you also want to support 2.5 or 2.4).

Anyway, if you're supporting both 2 and 3, a common code base offers many attractions, so if it can be done, it will. And 2to3 is a good approach to maintaining a common code base.

Not in the experience of the folks who are actually doing that task: the overhead of running 2to3 every time 'setup.py develop' etc. runs dooms the effort. For instance, we have a report that the 2to3 step takes more than half an hour (on at least one user's development machine) when installing / refreshing zope.interface in a Python 3.2 virtualenv. (Note that I'm in the process of getting that package's unit test coverage up to snuff before ripping out the 2to3 support in favor of a subset).

Using 2to3 during ongoing development makes Python feel like Java/C++, where "get a cup of coffee while we rebuild the world" is a frequent occurence.

Tres. - --

Tres Seaver +1 540-429-0999 tseaver at palladion.com Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

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