[Python-Dev] Reserve ':=' for type-inferred variable initialization (was PEP 572)

[Steven D'Aprano]

On Fri, Apr 27, 2018 at 10:56:06PM +1000, Nick Coghlan wrote:
> On 27 April 2018 at 22:28, Steven D'Aprano <steve at pearwood.info> wrote:
> 
> > On Fri, Apr 27, 2018 at 08:13:20AM +0200, Andrea Griffini wrote:
> > > Now we got standard library features requiring type annotation
> >
> > We do? Did I miss them? Which std lib features are you referring to?
> >
> > (That's not a rhetorical question -- maybe I have missed something.)
> >
> 
> Data classes rely on the presence of annotations to spot field declarations
> (it mostly doesn't care what those annotations actually say, but it does
> need them to be present in order to create the list of field names).

Thanks Nick. But they're not exactly used as *type* annotations.

It was inevitable that something in the std lib would eventually make 
use of annotations, but unless they're used for type-checking, that's 
hardly eating away at the promise "no mandatory static typing".


-- 
Steve