[Python-Dev] notes from "2 to 3 porting" session of Python Language Summit at PyCon

Thu Mar 26 23:37:54 CET 2009

My notes from the "2 to 3 porting" session of Python Language Summit at 
PyCon. There were some agreements in this session that people wanted 
recorded. Happy to provide clarification in my notes aren't clear.
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## python 2 to 3 migration
- 2to3 distutils flag (part of install or sdist)
- 2to3 is slow: lots of room for speedup (esp. on the matching)
- 3to2
 - good, wanted, needed: esp. by module authors
 - brett: volunteers? silence. Benjamin? Google SOC. Jesse volunteered to
 mentor.
 - decision: want to look into it
 - Want target compat 2.x (which "x"). Can be done by selecting 
appropriate
 fixers.
 - some discussion of dict views, etc.
- 2.x branch:
 - decision: 18 to 24 month btwn releases.
 - decision: 2.7 (2.6?) *might* be the end of the 2.x line.
- 3.1:
 - in alpha now
 - a2 during the sprints (Brett channeling Benjamin)
 - MvL still has a couple PEPs he wants to propose
 - Jython: considering targetting 3.2 next, *then* maybe 2.7
 - 3.1 will be the one exception to 18-24 mos.
- on "18-24 mo": start a release date PEP with a feature freeze date 
stake in
 the ground when the prev ver is released
- 3.0: special case, not doing 5 years of security releases...
 - hence 3.1 being released soon
 - linux distro guys are fine with that
- extension docs for porting still missing:
 - brett: Benjamin has a draft
 - PortingToPy3k in the wiki
 - Gerhard: doing it against svn
- the other Python implementations: what ver to target
 - depends on their audiences
 - Jython leaning on the latest 3
 - IronPython doesn't want a moving target
 - skip 3.0 and go for 3.1
- python2 & python3 binaries:
 - make install should do it
 - "python3" for new and forever
 - or "python2" for Python 2.x release? Thomas: bad idea because usage of
 "python2" in the shebang line will only work on newer systems
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Trent
--
Trent Mick
trentm at gmail.com
trentm at activestate.com