(original) (raw)
>> We're focused on Python 3.8 and 3.9, not Python 5 or Python 6.
Hmmm... When I was hearing the repeated belated saying that Python will never ever jump
on the statically typed ship on each and every static type annotation discussion I started to
worry this wasn't indeed the case (why the urge of repeating it so much otherwise?).
Now we got standard library features requiring type annotation and a little shift
towards a "not now" position.
I'm just wondering... I'm NOT saying this would be bad (or good).
On Fri, Apr 27, 2018 at 2:36 AM, Steven D'Aprano <steve@pearwood.info> wrote:
Hi Fatty, and welcome!
On Thu, Apr 26, 2018 at 08:00:55PM +0200, Fatty Morgan wrote:
\> The natural interpretation of 'name := expr' is a PEP 526
\> type-annotated variable initialization 'name : T = expr' with the
\> type annotation T omitted, the tokens ':' and '=' coalesced, and
\> the implied type T inferred as 'type(expr)'.
I'm not sure why you say that is the "natural" interpretation,
unless you're saying that Guido, Chris, myself and dozens of other
people taking part of this conversation are unnatural, since none of us
thought of that interpretation \*smiles\*
The := token is the second most common assignment operator in
programming languages, behind only = single equals sign. For those of us
who were raised on Pascal, it is entirely natural to use = for equality
tests and := for assignment, and languages that use == for equality are
the ones which are weird.
Since type-annotations are still only used by a small proportion of
Python code and Python developers, I doubt that they will jump to the
interpretation of "explicit type hint with no type given".
If the type-checker can infer the type of the expression, there's no
need to use the colon at all.
name := expression # can infer type here
name = expression # why not just infer the type here?
So using : Type without the type is entirely unnecessary. The colon is
only needed when you have to specify a type manually.
Your comments about some entirely hypothetical "Python with enforced
static typing" are interesting but so blue-sky that I honestly doubt
that there's any point in discussing them now. We're focused on Python
3.8 and 3.9, not Python 5 or Python 6.
\--
Steve
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
Python-Dev mailing list
Python-Dev@python.org
https://mail.python.org/mailman/listinfo/python-dev
Unsubscribe: https://mail.python.org/mailman/options/python-dev/ agriff%40tin.it