On 11/9/21 9:02 AM, Guido van Rossum wrote:
> On Mon, Nov 8, 2021 at 10:29 PM Ethan Furman wrote:
>> The way I see it, the following should hold
>>
>> empty_flag = RegexFlag(0)
>> any_case = RegexFlag.IGNORECASE
>> any_case_on_any_line = RegexFlag.IGNORECASE | RegexF
On Wed, Nov 10, 2021 at 11:44 AM Ethan Furman wrote:
> I don't know if there's a formal name, but in my mind, if you have something
> you don't have nothing. If you have a
> barrel with nothing in it (not even air, just a hard vacuum) then saying you
> have nothing in that barrel is a true
> st
On 11/8/21 3:09 PM, Steven D'Aprano wrote:
> On Mon, Nov 08, 2021 at 01:43:03PM -0800, Ethan Furman wrote:
>> SomeFlag.nothing in SomeFlag.something <-- ???
>
> I don't think that consistency with other containers is particularly
> relevant here. More useful is consistency with other flag objec
On Mon, Nov 8, 2021 at 10:29 PM Ethan Furman wrote:
>
> The way I see it, the following should hold
>
> empty_flag = RegexFlag(0)
> any_case = RegexFlag.IGNORECASE
> any_case_on_any_line = RegexFlag.IGNORECASE | RegexFlag.MULTILINE
>
> any_case in empty_flag is False
> an
Cameron Simpson writes:
> On 08Nov2021 23:32, MRAB wrote:
> >A flag could be a member, but could a set of flags?
>
> Probably one flavour should raise a TypeError then with this comparison.
> I wouldn't want "member flag present in SomeFlag.something" and
> "set-of-members present in So
Tim Peters writes:
> [Ethan Furman ]
> > .. on the other hand, it seems that collections of related flags
> > are often treated as in set theory, where the empty set is a
> > member of any non-empty set.
>
> Not how any set theory I've ever seen works: a set S contains the
> empty set if a
On 9/11/21 7:29 pm, Ethan Furman wrote:
I've had a couple people tell me that they think of flags as sets, and
use set theory / set behavior to understand how flags and groups of
flags should interact.
If you're going to think of flags as sets, then 'i in flags' should
be equivalent to '((1 <<
On Tue, 9 Nov 2021 at 06:31, Ethan Furman wrote:
(IMO, Steven D'Aprano's comment above, which I don't think you have
responded to yet, is the clearest summary of the options here. I agree
with what he says, but just wanted to clarify one point below).
> I've had a couple people tell me that they
On 08/11/2021 21:43, Ethan Furman wrote:
When is an empty container contained by a non-empty container?
For example:
These examples are not at all analogous. `a in b` has different
meanings for different classes of b.
{} in {1:'a', 'b':2] <-- TypeError because of hashability
`x in aDict`
Something to keep in mind as these discussions continue: Enums are already
unusual in several ways:
- the class itself is iterable
- the class itself supports containment checks of its enum members
- the enum members are created, and guaranteed singletons, during class creation
- the enum membe
On Mon, Nov 8, 2021 at 7:26 PM Ethan Furman wrote:
> Let's use a concrete example: `re.RegexFlag`
>
> ```
> Help on function match in module re:
>
> match(pattern, string, flags=0)
> Try to apply the pattern at the start of the string, returning
> a Match object, or None if no match wa
Let's use a concrete example: `re.RegexFlag`
```
Help on function match in module re:
match(pattern, string, flags=0)
Try to apply the pattern at the start of the string, returning
a Match object, or None if no match was found.
```
In use we have:
result = re.match('present', 'who
I think he's confusing the fact that empty is a subset of every set
___
Python-Dev mailing list -- python-dev@python.org
To unsubscribe send an email to python-dev-le...@python.org
https://mail.python.org/mailman3/lists/python-dev.python.org/
Message arch
On Mon, Nov 8, 2021 at 1:43 PM Ethan Furman wrote:
> When is an empty container contained by a non-empty container?
>
> For example:
>
> {} in {1:'a', 'b':2} <-- TypeError because of hashability
>
(You accidentally wrote a square close bracket, but I know you meant a
curly close brace. :-}
>
On 2021-11-09 00:27, Cameron Simpson wrote:
On 08Nov2021 23:32, MRAB wrote:
>On 2021-11-08 22:10, Cameron Simpson wrote:
>>>{} in {1:'a', 'b':2] <-- TypeError because of hashability
>>>set() in {1, 2, 'a', 'b'} <-- ditto
>>>[] in ['a', 'b', 1, 2] <-- False
>>
>>Right. Also, the members are n
On 08Nov2021 23:32, MRAB wrote:
>On 2021-11-08 22:10, Cameron Simpson wrote:
>>>{} in {1:'a', 'b':2] <-- TypeError because of hashability
>>>set() in {1, 2, 'a', 'b'} <-- ditto
>>>[] in ['a', 'b', 1, 2] <-- False
>>
>>Right. Also, the members are not dicts or sets, respectively.
>>
>More preci
On 2021-11-08 22:10, Cameron Simpson wrote:
Note: I know you understand all this, I'm not "explaining" how things
work below, I'm explaining how/why I think about how these work.
On 08Nov2021 13:43, Ethan Furman wrote:
When is an empty container contained by a non-empty container?
[...]
For
On Mon, Nov 08, 2021 at 01:43:03PM -0800, Ethan Furman wrote:
> When is an empty container contained by a non-empty container?
[...]
> SomeFlag.nothing in SomeFlag.something <-- ???
I don't think that consistency with other containers is particularly
relevant here. More useful is consistency w
[Ethan Furman ]
> When is an empty container contained by a non-empty container?
That depends on how the non-empty container's type defines
__contains__. The "stringish" types (str, byte, bytearray) work _very_
differently from others (list, set, tuple) in this respect.
t in x
for the latter
Note: I know you understand all this, I'm not "explaining" how things
work below, I'm explaining how/why I think about how these work.
On 08Nov2021 13:43, Ethan Furman wrote:
>When is an empty container contained by a non-empty container?
[...]
>For example:
>
>{} in {1:'a', 'b':2] <-- TypeErr
20 matches
Mail list logo
