PEP suggestion: Uniform way to indicate Python language version

[Random832]

On Mon, Aug 22, 2016, at 01:35, Steven D'Aprano wrote:
> Could somebody (the OP?) please explain what is the purpose of this
> proposal, what it does, how it works, and when would people use it?

I think what he wants is a way for a module which uses features
(syntactic or otherwise, but I suppose especially syntactic features
since this can't as easily be done with a runtime check using existing
mechanisms) from a particular python version and which makes no
provision to run under earlier versions to fail with a message like
"This script requires Python 3.4 or later" rather than a mysterious
syntax error or worse a runtime error after the program has been running
for some time.