Issue 26095: Update porting HOWTO to special-case Python 2 code, not Python 3 (original) (raw)

This issue has been migrated to GitHub: https://github.com/python/cpython/issues/70283

classification

process

Created on 2016-01-13 02:16 by brett.cannon, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (4)
msg258126 - (view)	Author: Brett Cannon (brett.cannon) *	Date: 2016-01-13 02:16
As pointed out by http://astrofrog.github.io/blog/2016/01/12/stop-writing-python-4-incompatible-code/, special-casing Python 3 code instead of Python 2 code when writing Python 2/3 code will lead to breakage when Python 3 comes out. There should probably be a note in the porting HOWTO mentioning that you should always special-case Python 2 code and not Python 3 code.
msg258127 - (view)	Author: Brett Cannon (brett.cannon) *	Date: 2016-01-13 02:17
And suggesting feature detection is even better than version detection.
msg258130 - (view)	Author: Alyssa Coghlan (ncoghlan) *	Date: 2016-01-13 04:33
The feature detection approach is especially important for anything covered by the security backports in PEP 466 and 476, but can also apply for things like installing the importlib2 meta_path hooks into Python 2.7.
msg261992 - (view)	Author: Roundup Robot (python-dev)	Date: 2016-03-18 20:24
New changeset a2bf6d1e018e by Brett Cannon in branch 'default': Merge for issue #26095 https://hg.python.org/cpython/rev/a2bf6d1e018e