Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On 2018-04-12 18:03, Guido van Rossum wrote: It's a slippery slope indeed. While having to change update() alone wouldn't worry me, the subclass constructors do seem like they are going to want changing too, and that's indeed a bit much. So let's back off a bit. Not every three lines of code

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

12.04.18 22:42, Andrés Delfino пише: I think the update method can (and personally, should) stay unchanged: spam.update(dict(x, y)) seems succinct and elegant enough, with the proposed constructor syntax. Sorry my ignorance, do (Mutable)Mapping ABC say anything about constructors? Mapping

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

There's a long thread about the subject: https://mail.python.org/pipermail/python-ideas/2015-February/031748.html I suggest to avoid the matter altogether :) On Thu, Apr 12, 2018 at 4:15 PM, Mike Miller wrote: > While we're on the subject, I've tried to add dicts a

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

While we're on the subject, I've tried to add dicts a few times over the years to get a new one but it doesn't work: d3 = d1 + d2 # TypeError Thinking a bit, set union is probably a better analogue, but it doesn't work either: d3 = d1 | d2 # TypeError Where the last value of any

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On Thu, Apr 12, 2018 at 7:34 AM, Ed Kellett wrote: > On 2018-04-12 14:46, Andrés Delfino wrote: > > Extending the original idea, IMHO it would make sense for the dict > > constructor to create a new dictionary not only from several mappings, > but > > mixing mappings

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On 2018-04-12 14:46, Andrés Delfino wrote: > Extending the original idea, IMHO it would make sense for the dict > constructor to create a new dictionary not only from several mappings, but > mixing mappings and iterables too. > > Consider this example: > > x = [(1, 'one')] > y = {2: 'two'} > >

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

Extending the original idea, IMHO it would make sense for the dict constructor to create a new dictionary not only from several mappings, but mixing mappings and iterables too. Consider this example: x = [(1, 'one')] y = {2: 'two'} Now: {**dict(x), **y} Proposed: dict(x, y) I think this

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

Ok, we can haggle the finer details and I admit once you learn the syntax it isn't substantially harder. Simply, I've found the dict() a bit easier to mentally parse at a glance. Also, to add I've always expected multiple args to work with it, and am always surprised when it doesn't. Would

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On Wed, Apr 11, 2018 at 2:44 PM, Steven D'Aprano wrote: > On Wed, Apr 11, 2018 at 02:22:08PM +1000, Chris Angelico wrote: > >> > dict(d1, d2, d3) >> >> That's more readable than {**d1, **d2, **d3} ? Doesn't look materially >> different to me. > > It does to me. > > On the

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On Wed, Apr 11, 2018 at 02:22:08PM +1000, Chris Angelico wrote: > > dict(d1, d2, d3) > > That's more readable than {**d1, **d2, **d3} ? Doesn't look materially > different to me. It does to me. On the one hand, we have a function call (okay, technically a type...) "dict()" that can be

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On Wed, Apr 11, 2018 at 11:19 AM, Mike Miller wrote: > > On 2018-04-09 04:23, Daniel Moisset wrote: >> >> In which way would this be different to {**mapping1, **mapping2, >> **mapping3} ? > > > That's possible now, but believe the form mentioned previously would be more

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

On 2018-04-09 04:23, Daniel Moisset wrote: In which way would this be different to {**mapping1, **mapping2, **mapping3} ? That's possible now, but believe the form mentioned previously would be more readable: dict(d1, d2, d3) -Mike ___

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

No worries, already implemented features happens so often in this list that there's a story about Guido going back in a time machine to implement them ;-) Just wanted to check that I had understood what you suggested correctly On 9 April 2018 at 12:42, Andrés Delfino wrote:

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

Sorry, I didn't know that kwargs unpacking in dictionaries displays don't raise a TypeError exception. On Mon, Apr 9, 2018 at 8:23 AM, Daniel Moisset wrote: > In which way would this be different to {**mapping1, **mapping2, > **mapping3} ? > > On 8 April 2018 at 22:18,

Re: [Python-ideas] Accepting multiple mappings as positional arguments to create dicts

In which way would this be different to {**mapping1, **mapping2, **mapping3} ? On 8 April 2018 at 22:18, Andrés Delfino wrote: > Hi! > > I thought that maybe dict could accept several mappings as positional > arguments, like this: > > class Dict4(dict): >> def

[Python-ideas] Accepting multiple mappings as positional arguments to create dicts

Hi! I thought that maybe dict could accept several mappings as positional arguments, like this: class Dict4(dict): > def __init__(self, *args, **kwargs): > if len(args) > 1: > if not all([isinstance(arg, dict) for arg in args]): > raise TypeError('Dict4