syntax difference

[Rick Johnson]

On Tuesday, June 19, 2018 at 5:21:25 AM UTC-5, Chris Angelico wrote:
> On Tue, Jun 19, 2018 at 8:12 PM, Steven D'Aprano
> <steve+comp.lang.python at pearwood.info> wrote:
> > On Mon, 18 Jun 2018 11:34:40 -0700, Jim Lee wrote:
> >
> >> On 06/18/2018 11:18 AM, Chris Angelico wrote:
> >>> What, fundamentally, is the difference between type hints and
> >>> assertions, such that - in
> >>> your view - one gets syntax and the other is just comments?
> >> Type hints are just that - hints.  They have no syntactic meaning to the
> >> parser, and do not affect the execution path in any way. Therefore, they
> >> are effectively and actually comments.  The way they have been
> >> implemented, though, causes noise to be interspersed with live code and,
> >> as others have said, are difficult to remove or ignore.
> >
> > So let me get this straight...
> >
> > Using annotations is evil, because it intersperses noise with live code:
> >
> > def function(argument: int,
> >              flag: bool,
> >              sequence: list) -> str:
> >     ...
> >
> >
> > But using comments is great, because it doesn't:
> >
> > def function(argument,  # type=int,
> >              flag,  # type=bool,
> >              sequence, # type=list):  # type=str
> >     ...
> >
> >
> > Okay, I'm glad we cleared that up.
> >
> 
> Isn't it nice how comments, being terminated exclusively by
> end-of-line, allow the introduction of subtle bugs? Let's see how many
> people spot the (presumably deliberate) bug in Steve's code here.

It wasn't deliberate, Chris. But if Steven "presumably" wanted to show us why hanging comments are a code smell that most professional programmers will avoid, well, he certainly excelled at that, didn't he?