Guido van Rossum <gu...@python.org> writes: > On Sun, Nov 8, 2009 at 1:35 PM, Michael Foord <mich...@voidspace.org.uk> > wrote: > > Almost no-one is ever going to run Python with PendingDeprecation > > warnings switched on, so there should be at least one 'noisy' > > release in my opinion. > > I disagree. The -3 option is an example of a better approach: silent > by default, warnings enabled by a command line flag. If we can trust > developers to use -3 to check for Py3k incompatibilities, we should > also be able to trust them to check for deprecation warnings > explicitly.
That doesn't seem to follow. The Python 2 → Python 3 transition has received a *huge* amount of attention (in the Python world), to the point which pretty much the *only* thing many people know about Python 3 is “it breaks backward compatibility”. So it's not surprising that people are explicitly looking for ways to tell whether their code will break in the transition, and consequently many people using the ‘-3’ flag. I think this is a special case. A transition between minor versions of Python, on the other hand, does not inherently have the same clanging alarm bell associated with it: indeed, by contrast with Python 2 → Python 3, the message is that the upgrade from Python N.M → Python N.M+1 will be a *compatible* upgrade. I would expect consequently far fewer developers go actively looking for compatibility problems. > (Another argument to think about: if you download and install some 3rd > party code, deprecation warnings about that code are *only noise* > since they are not yours to fix. Warnings in a dynamic language work > very different than warnings in a compiled language.) Right, so the users can then pressure the third party to fix their code before it stops working altogether in a future version. When the user complains to the Python community, we can publicly shame the third party into testing and declaring their supported Python versions. After all, they only need to see whether it runs without warnings; they don't even need to remember to turn on any special flags. -- \ “Let others praise ancient times; I am glad I was born in | `\ these.” —Ovid (43 BCE–18 CE) | _o__) | Ben Finney _______________________________________________ stdlib-sig mailing list stdlib-sig@python.org http://mail.python.org/mailman/listinfo/stdlib-sig
