<div class="gmail_quote">On Thu Jan 22 2015 at 12:38:17 Chris Angelico <<a href="mailto:rosuav@gmail.com">rosuav@gmail.com</a>> wrote:<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
If you don't run the type checker, and the annotations will continue<br>
to do what they always have done. Seems easy enough.<br>
<br>
Supporting Python installations that already exist is as simple as<br>
either installing a backported typing.py, or not using a feature that<br>
didn't exist at that point. Same as the compatibility requirements of<br>
using enumerations in earlier versions of Python - you either grab the<br>
one off PyPI, or don't use 'em. I'm not seeing a problem here... have<br>
I missed something?<br></blockquote><div><br></div><div>Put simply, code can't support existing Python installations and future ones at the same time... unless it adds a dependency (is there a dummy typing.py available on PyPI?) or just doesn't use annotations for *anything*.</div><div><br></div><div>It's kind of like enumerations, except there aren't any proposals threatening to punish you for not using them.</div><div><br></div><div>Ed Kellett</div></div>