On 18Mar2019 08:10, Eric Fahlgren wrote:
On Mon, Mar 18, 2019 at 7:04 AM Rhodri James wrote:
On 18/03/2019 12:19, Richard Damon wrote:
> On 3/18/19 7:27 AM, Greg Ewing wrote:
>> Juancarlo Añez wrote:
>>
>>> if settings[MY_KEY] is True:
>>> ...
>>
>> If I saw code like this, it
18.03.19 22:52, Wes Turner пише:
>>> True = 1
File "", line 1
SyntaxError: can't assign to keyword
The error message will be changed in 3.8.
>>> True = 1
File "", line 1
SyntaxError: cannot assign to True
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18.03.19 22:58, Greg Ewing пише:
Oleg Broytman wrote:
Three-way (tri state) checkbox. You have to distinguish False and
None if the possible valuse are None, False and True.
In that case the conventional way to write it would be
if settings[MY_KEY] == True:
...
It's not a
On Tue, Mar 19, 2019 at 11:32:56AM +1300, Greg Ewing wrote:
> Tim Delaney wrote:
> >I would argue the opposite - the use of "is" shows a clear knowledge
> >that True and False are each a singleton and the author explicitly
> >intended to use them that way.
>
> I don't think you can infer that.
On Mon, Mar 18, 2019 at 3:42 PM Greg Ewing
wrote:
> Tim Delaney wrote:
> > I would argue the opposite - the use of "is" shows a clear knowledge
> > that True and False are each a singleton and the author explicitly
> > intended to use them that way.
>
> I don't think you can infer that. It could
Tim Delaney wrote:
I would argue the opposite - the use of "is" shows a clear knowledge
that True and False are each a singleton and the author explicitly
intended to use them that way.
I don't think you can infer that. It could equally well be someone who's
*not* familiar with Python truth
On Tue, Mar 19, 2019 at 09:58:55AM +1300, Greg Ewing wrote:
> Oleg Broytman wrote:
> > Three-way (tri state) checkbox. You have to distinguish False and
> >None if the possible valuse are None, False and True.
>
> In that case the conventional way to write it would be
>
> if
On Tue, 19 Mar 2019 at 08:42, Greg Ewing
wrote:
> Oleg Broytman wrote:
> >Three-way (tri state) checkbox. You have to distinguish False and
> > None if the possible valuse are None, False and True.
>
> In that case the conventional way to write it would be
>
> if settings[MY_KEY] ==
There are few cases where I would approve of 'if x is True'. However, the
names used in the example suggest it could be one of those rare cases.
Settings of True/False/None (i.e. not set) seem like a reasonable pattern.
In fact, in code like that, merely "truthy" values are probably a bug that
It was a VERY long time ago when True and False were not singletons. I
don't think we should still try to write code based on rules that stopped
applying more than a decade ago.
On Mon, Mar 18, 2019, 5:42 PM Greg Ewing
wrote:
> Oleg Broytman wrote:
> >Three-way (tri state) checkbox. You
Richard Damon wrote:
On 3/18/19 7:27 AM, Greg Ewing wrote:
if settings[MY_KEY]:
...
>
That means something VERY different.
Yes, but there needs to be justification for why the difference
matters and why this particular way is the best way to deal
with it.
Whenever you write 'x
Oleg Broytman wrote:
Three-way (tri state) checkbox. You have to distinguish False and
None if the possible valuse are None, False and True.
In that case the conventional way to write it would be
if settings[MY_KEY] == True:
...
It's not a major issue, but I get nervous when I
On Tue, Mar 19, 2019 at 7:53 AM Wes Turner wrote:
>
> 'True' is a keyword. (Which is now immutable in Python 3.X?)
>
> >>> True = 1
> File "", line 1
> SyntaxError: can't assign to keyword
In Python 3, the source code token "True" is a keyword literal that
always represents the bool value
'True' is a keyword. (Which is now immutable in Python 3.X?)
>>> True = 1
File "", line 1
SyntaxError: can't assign to keyword
https://docs.python.org/3/reference/datamodel.html#the-standard-type-hierarchy
https://docs.python.org/3/search.html?q=singleton
- "Since None is a singleton,
On 18/03/2019 15:10, Eric Fahlgren wrote:
On Mon, Mar 18, 2019 at 7:04 AM Rhodri James wrote:
On 18/03/2019 12:19, Richard Damon wrote:
On 3/18/19 7:27 AM, Greg Ewing wrote:
Juancarlo Añez wrote:
if settings[MY_KEY] is True:
...
If I saw code like this, it would take a
On Mon, Mar 18, 2019 at 7:04 AM Rhodri James wrote:
> On 18/03/2019 12:19, Richard Damon wrote:
> > On 3/18/19 7:27 AM, Greg Ewing wrote:
> >> Juancarlo Añez wrote:
> >>
> >>> if settings[MY_KEY] is True:
> >>> ...
> >>
> >> If I saw code like this, it would take a really good
On 18/03/2019 12:19, Richard Damon wrote:
On 3/18/19 7:27 AM, Greg Ewing wrote:
Juancarlo Añez wrote:
if settings[MY_KEY] is True:
...
If I saw code like this, it would take a really good argument to
convince me that it shouldn't be just
if settings[MY_KEY]:
...
On Tue, Mar 19, 2019 at 12:27:04AM +1300, Greg Ewing
wrote:
> Juancarlo A?ez wrote:
>
> >if settings[MY_KEY] is True:
> >...
>
> If I saw code like this, it would take a really good argument to
> convince me that it shouldn't be just
>
> if settings[MY_KEY]:
> ...
On 3/18/19 7:27 AM, Greg Ewing wrote:
> Juancarlo Añez wrote:
>
>> if settings[MY_KEY] is True:
>> ...
>
> If I saw code like this, it would take a really good argument to
> convince me that it shouldn't be just
>
> if settings[MY_KEY]:
> ...
>
That means something VERY
On 3/18/19 7:32 AM, Chris Angelico wrote:
> On Mon, Mar 18, 2019 at 10:14 PM Juancarlo Añez wrote:
>> It came to my attention that:
>>
>> In the original PEP True and False are said to be singletons
>> https://www.python.org/dev/peps/pep-0285/, but it's not in the Data Model
>>
Juancarlo Añez wrote:
if settings[MY_KEY] is True:
...
If I saw code like this, it would take a really good argument to
convince me that it shouldn't be just
if settings[MY_KEY]:
...
--
Greg
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On Mon, Mar 18, 2019 at 10:14 PM Juancarlo Añez wrote:
>
> It came to my attention that:
>
> In the original PEP True and False are said to be singletons
> https://www.python.org/dev/peps/pep-0285/, but it's not in the Data Model
> https://docs.python.org/3/reference/datamodel.html
>
>
> This
Le 18 mars 2019 à 12:15:05, Juancarlo Añez
(apal...@gmail.com(mailto:apal...@gmail.com)) a écrit:
> It came to my attention that:
>
> > In the original PEP True and False are said to be singletons
> > https://www.python.org/dev/peps/pep-0285/, but it's not in the Data Model
> >
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