Re: [Python-Dev] PEP 572: Assignment Expressions

> On Apr 19, 2018, at 4:27 PM, Christoph Groth wrote: > def sync_runner(learner, f, static_hint): >while True: >points = learner.get(static_hint) >if not points: >break >learner.feed(f(points)) > > > > With assignment

Re: [Python-Dev] PEP 572: Now with 25% less reference implementation!

Hello Chris, and thank you for working on this PEP! What do you think about using variable type hints with this syntax? I tried to search through python-dev and couldn't find a single post discussing that question. If I missed it somehow, could you please include its conclusions into the PEP?

[Python-Dev] PEP 572: Assignment Expressions

Christoph Groth writes: > Wouldn't it be a pity not to liberate assignments from their boring > statement existence? Maybe not. While it would be nice to solve the loop-and-a-half "problem" and the loop variable initialization "problem" (not everyone agrees these are even problems, especially

[Python-Dev] PEP 572: Now with 25% less reference implementation!

Working on the reference implementation for PEP 572 is turning out to be a massive time sink, both on my personal schedule and on the PEP's discussion. I can't just hold off all discussion on a topic until I figure out whether something is possible or not, because that could take me several days,

[Python-Dev] PEP 572: Assignment Expressions

I'd like to break a lance for PEP 572. I read that in the bad old days Python used to have a "=" operator in expressions that had the meaning of today's "==". Perhaps there were other reasons, but this choice alone meant that assignment (that was using the same token) could not be made an

Re: [Python-Dev] PEP 572: Assignment Expressions

On Thu, Apr 19, 2018 at 5:45 AM, Nick Coghlan wrote: > * for the while loop use case, I think my discussion with Tim about > tuple unpacking shows that the loop-and-a-half construct won't be > going anywhere, so users would still end up needing to learn both > forms (even for

Re: [Python-Dev] PEP 572: Assignment Expressions

On 19 April 2018 at 02:38, Brett Cannon wrote: > I'm also -1. > > I understand the usefulness of the construct in languages where block scopes > make having this kind of expression assignment in e.g. an 'if' guard useful. > But for Python and it's LGB scoping -- although I think

Re: [Python-Dev] PEP 572: Assignment Expressions

On 19 April 2018 at 02:18, Guido van Rossum wrote: > On Wed, Apr 18, 2018 at 7:35 AM, Chris Angelico wrote: >> >> On Wed, Apr 18, 2018 at 11:58 PM, Guido van Rossum >> wrote: >> 2) Genexps will eagerly evaluate a lookup if it happens to be

Re: [Python-Dev] PEP 572: Assignment Expressions

MRAB wrote: Some languages use '=' for assignment, others for equality, but do you know of a language that uses ':=' for equality' or '==' for assignment? No, but the only sane reason to use "==" for equality testing seems to be if you're already using "=" for something else. So maybe we

Re: [Python-Dev] Timing for removing legacy Unicode APIs deprecated by PEP 393

> > I suppose that many users will start porting to Python 3 only in 2020, after > 2.7 EOL. After that time we shouldn't support compatibility with 2.7 and can > start emitting deprecation warnings at runtime. After 1 or 2 releases after > that we can make corresponding public API always failing