On 2/6/06, Guido van Rossum <[EMAIL PROTECTED]> wrote:
> On 2/6/06, Donovan Baarda <[EMAIL PROTECTED]> wrote:
> > yeah... the problem is differentiating the empty set from an empty dict.
> > The only alternative that occured to me was the not-so-nice and
> > not-backwards-compatible "{:}" for an em
Donovan Baarda <[EMAIL PROTECTED]> wrote:
>
> On Fri, 2006-02-03 at 11:56 -0800, Josiah Carlson wrote:
> > Along the lines of "not every x line function should be a builtin", "not
> > every builtin should have syntax". I think that sets have particular
> > uses, but I don't believe those uses ar
On 2/6/06, Donovan Baarda <[EMAIL PROTECTED]> wrote:
> yeah... the problem is differentiating the empty set from an empty dict.
> The only alternative that occured to me was the not-so-nice and
> not-backwards-compatible "{:}" for an empty dict and "{}" for an empty
> set.
How about spelling the e
On Mon, 2006-02-06 at 15:36 +0100, Ronald Oussoren wrote:
> On Monday, February 06, 2006, at 03:12PM, Donovan Baarda <[EMAIL PROTECTED]>
> wrote:
>
> >On Fri, 2006-02-03 at 20:02 +0100, "Martin v. Löwis" wrote:
> >> Donovan Baarda wrote:
> >> > Before set() the standard way to do them was to use
On Monday, February 06, 2006, at 03:12PM, Donovan Baarda <[EMAIL PROTECTED]>
wrote:
>On Fri, 2006-02-03 at 20:02 +0100, "Martin v. Löwis" wrote:
>> Donovan Baarda wrote:
>> > Before set() the standard way to do them was to use dicts with None
>> > Values... to me the "{1,2,3}" syntax would have
On Fri, 2006-02-03 at 20:02 +0100, "Martin v. Löwis" wrote:
> Donovan Baarda wrote:
> > Before set() the standard way to do them was to use dicts with None
> > Values... to me the "{1,2,3}" syntax would have been a logical extension
> > of the "a set is a dict with no values, only keys" mindset. I
On Fri, 2006-02-03 at 11:56 -0800, Josiah Carlson wrote:
> Donovan Baarda <[EMAIL PROTECTED]> wrote:
[...]
> > Nuff was a fairy... though I guess it depends on where you draw the
> > line; should [1,2,3] be list(1,2,3)?
>
> Who is "Nuff"?
fairynuff... :-)
> Along the lines of "not every x line f
> > > Raymond:
> > > Accordingly,Guido rejected the braced notation for set comprehensions.
> > > See: http://www.python.org/peps/pep-0218.html
> > Greg:
> > "...however, the issue could be revisited for Python 3000 (see PEP 3000)."
> > So I'm only 1994 years early ;-)
> Alex:
> Don't be such a
Donovan Baarda <[EMAIL PROTECTED]> wrote:
>
> On Fri, 2006-02-03 at 09:00 -0800, Josiah Carlson wrote:
> [...]
> > Sets are tacked on. That's why you need to use 'import sets' to get to
> > them, in a similar fashion that you need to use 'import array' to get
> > access to C-like arrays.
>
> No
Donovan Baarda wrote:
> Before set() the standard way to do them was to use dicts with None
> Values... to me the "{1,2,3}" syntax would have been a logical extension
> of the "a set is a dict with no values, only keys" mindset. I don't know
> why it wasn't done this way in the first place, though
On Fri, 2006-02-03 at 09:00 -0800, Josiah Carlson wrote:
[...]
> Sets are tacked on. That's why you need to use 'import sets' to get to
> them, in a similar fashion that you need to use 'import array' to get
> access to C-like arrays.
No you don't;
$ python
Python 2.4.1 (#2, Mar 30 2005, 21:51:1
Donovan Baarda <[EMAIL PROTECTED]> wrote:
>
> On Wed, 2006-02-01 at 13:55 -0500, Greg Wilson wrote:
> > Hi,
> >
> > I have a student who may be interested in adding syntactic support for
> > sets to Python, so that:
> >
> > x = {1, 2, 3, 4, 5}
> >
> > and:
> >
> > y = {z for z in x if
On Fri, 2006-02-03 at 12:04 +, Donovan Baarda wrote:
> On Wed, 2006-02-01 at 13:55 -0500, Greg Wilson wrote:
[...]
> Personally I'd like this. currently the "set(...)" syntax makes sets
> feel tacked on compared to tuples, lists, dicts, and strings which have
> nice built in syntax support. Ma
Donovan Baarda wrote:
> For Python 3000 you could extend this approach to lists and dicts;
> [1,2,3] is a list, f[1,2,3] is a "frozen list" or tuple, {1:'a',2:'b'}
> is a dict, f{1:'a',2:'b'} is a "frozen dict" which can be used as a key
> in other dicts... etc.
Traceback (most recent call last):
On Wed, 2006-02-01 at 13:55 -0500, Greg Wilson wrote:
> Hi,
>
> I have a student who may be interested in adding syntactic support for
> sets to Python, so that:
>
> x = {1, 2, 3, 4, 5}
>
> and:
>
> y = {z for z in x if (z % 2)}
Personally I'd like this. currently the "set(...)" synta
On 2/1/06, Greg Wilson <[EMAIL PROTECTED]> wrote:
> > Generator expressions make syntactic support irrelevant:
>
> Not when you're teaching the language to undergraduates: I haven't
> actually done the study yet (though I may this summer), but I'm willing to
> bet that allowing "math" notation for
On Wed, 1 Feb 2006, Greg Wilson wrote:
[...]
> (Imagine having to write "list(1, 2, 3, 4, 5)"...)
[...]
I believe that was actually proposed on this list for Python 3.
John
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On Wed, 1 Feb 2006, Greg Wilson wrote:
>> Like many things in Python where people pre-emptively believe one thing
>> or another, the interpreter's corrective feedback is immediate:
>
> Yup, that's the theory; it's a shame practice is different.
So what mistake(s) *do* your students make? As peop
> Like many things in Python where people pre-emptively believe one thing
> or another, the interpreter's corrective feedback is immediate:
Yup, that's the theory; it's a shame practice is different.
> Once the students have progressed beyond academic finger drills and have
> started writing real
> The PEP records that Tim argued for leaving the extra parentheses. What
> would you do with {'title'} -- create a four element set consisting of
> letters or a single element set consisting of a string?
This is a moderately-fertile source of bugs for newcomers: judging from
the number of student
> Generator expressions make syntactic support irrelevant:
Not when you're teaching the language to undergraduates: I haven't
actually done the study yet (though I may this summer), but I'm willing to
bet that allowing "math" notation for sets will more than double their
use. (Imagine having to w
On Wed, Feb 01, 2006 at 03:03:22PM -0500, Phillip J. Eby wrote:
> The only case that looks slightly less than optimal is:
>
> set((1, 2, 3, 4, 5))
>
> But I'm not sure that it warrants a special syntax just to get rid of the
> extra ().
In any case I don't think it's possible to differenti
[Greg Wilson]
> This is a moderately-fertile source of bugs for newcomers: judging from
> the number of students who come into my office with code that they think
> ought to work, but doesn't, most people believe that:
>
>set(1, 2, 3)
Like many things in Python where people pre-emptively beli
Raymond Hettinger wrote:
> [Phillip J. Eby]
> > The only case that looks slightly less than optimal is:
> >
> >set((1, 2, 3, 4, 5))
> >
> > But I'm not sure that it warrants a special syntax just to get rid of the
> > extra ().
>
> The PEP records that Tim argued for leaving the extra parenthes
[Phillip J. Eby]
> The only case that looks slightly less than optimal is:
>
>set((1, 2, 3, 4, 5))
>
> But I'm not sure that it warrants a special syntax just to get rid of the
> extra ().
The PEP records that Tim argued for leaving the extra parentheses.
What would you do with {'title'} -- cr
At 01:55 PM 2/1/2006 -0500, Greg Wilson wrote:
>I have a student who may be interested in adding syntactic support for
>sets to Python, so that:
>
> x = {1, 2, 3, 4, 5}
>
>and:
>
> y = {z for z in x if (z % 2)}
>
>would be legal. There are of course issues (what's the syntax for a
>frozen
[Greg Wilson]
> I have a student who may be interested in adding syntactic support for
> sets to Python, so that:
>
>x = {1, 2, 3, 4, 5}
>
> and:
>
>y = {z for z in x if (z % 2)}
>
> would be legal. There are of course issues (what's the syntax for a
> frozen set? for the empty set?),
On 2/1/06, Greg Wilson <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I have a student who may be interested in adding syntactic support for
> sets to Python, so that:
>
> x = {1, 2, 3, 4, 5}
>
> and:
>
> y = {z for z in x if (z % 2)}
>
> would be legal. There are of course issues (what's the syntax
Hi,
I have a student who may be interested in adding syntactic support for
sets to Python, so that:
x = {1, 2, 3, 4, 5}
and:
y = {z for z in x if (z % 2)}
would be legal. There are of course issues (what's the syntax for a
frozen set? for the empty set?), but before he even starts, I'
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