[Python-Dev] Should we move to replace re with regex?

[Virgil Dupras]

On 2011-08-27, at 2:20 PM, Dan Stromberg wrote:

> 
> On Sat, Aug 27, 2011 at 9:53 AM, Brian Curtin <brian.curtin at gmail.com> wrote:
> On Sat, Aug 27, 2011 at 11:48, Dan Stromberg <drsalists at gmail.com> wrote:
> No, this was not the intent of __future__. The intent is that a
> feature is desirable but also backwards incompatible (e.g. introduces
> a new keyword) so that for 1 (sometimes more) releases we require the
> users to use the __future__ import.
> 
> There was never any intent to use __future__ for experimental
> features. If we want that maybe we could have from __experimental__
> import <whatever>.
> 
> OK.  So what -is- the purpose of from __future__ import?
> 
> It's in the first paragraph. 
> 
> I disagree.  The first paragraph says this has something to do with new keywords.  It doesn't appear to say what we expect users to -do- with it.  Both are important.
> 
> Is it "You'd better try this, because it's going in eventually.  If you don't try it out before it becomes default behavior, you have no right to complain"?
> 
> And if people do complain, what are python-dev's options?
> 

__future__ imports have nothing to do with "trying stuff before it comes", it has to do with backward compatibility. For example, the "with_statement" was a __future__ import because introducing the "with" keyword would break any code using "with" as a token. I don't think that the goal of introducing "with" as a future import was "we're gonna see how it pans out, and decide if we really introduce it later".

__future__ means "It's coming, prepare your code".