[Python-ideas] [Python-ideos] Dedicated overloadable boolean operators

[Michael Selik]

Why hasn't SQLAlchemy gone the route of NumPy with overloaded operators?
Perhaps whatever reason it is would prevent using any new operators as well.

With NumPy I make that mistake constantly:
    A == a & B == b
rather than
    (A == a) & (B == b)

I'd put that in the category of parentheses tax along with the print
function and old style % string interpolation. Annoying, but it's
inappropriate to use a gun to swat a fly. (In case my metaphor is unclear,
creating a new operator is the gun -- risking collateral damage and all
that)

As Guido said, the real usability problem is that the ``and`` operator is a
new Python programmer's first instinct. Adding yet another operator would
make Python harder to learn and read. Even if you advertise a new operator,
many libraries will be slow to change and we'll have 3 different techniques
to teach. Let's weigh the benefits against the negative consequences.

On Mon, Nov 23, 2015 at 8:12 PM Jelte Fennema <me at jeltef.nl> wrote:

> On 24 November 2015 at 01:26, Bruce Leban <bruce at leban.us> wrote:
>
>> If this idea were to fly, a better name would be something that doesn't
>> have that problem, e.g., .and. .or. .not. I don't want to bikeshed the
>> exact syntax**, but I think it should be clear that with something like
>> this: (1) no one is going to accidentally type them and (2) they are pretty
>> clearly some variation of the standard and/or/not.
>
>
> I think a naming scheme like that is indeed a good way to solve the
> confusion issues, since it is also immediately clear that these would be a
> special version of the normal operators. Another advantage is that it could
> also be extended to the in operator, if that one is to be included.
>
> I'm not sure I like the dots version very much though, but like you said
> there are lots of syntax error options to choose from.
>
> On 24 November 2015 at 01:26, Bruce Leban <bruce at leban.us> wrote:
>
>>
>> On Mon, Nov 23, 2015 at 4:08 PM, Chris Angelico <rosuav at gmail.com> wrote:
>>
>>> I think it's reasonable, except for the potential confusion of having
>>> *three* "and" operators.
>>>
>>
>> I think using && and || would be an attractive nuisance for people
>> switching from another programming language. Right now if I accidentally
>> right && in Python or "and" in another language, I get an immediate syntax
>> error. With this proposal, I get unexpected results.
>>
>> If this idea were to fly, a better name would be something that doesn't
>> have that problem, e.g., .and. .or. .not. I don't want to bikeshed the
>> exact syntax**, but I think it should be clear that with something like
>> this: (1) no one is going to accidentally type them and (2) they are pretty
>> clearly some variation of the standard and/or/not.
>>
>> **Lots of other possibilities that are syntax errors right now: @and, (and),
>> etc. I like .and. because it's less visual clutter and it's easy to type.
>>
>> --- Bruce
>> Check out my puzzle book and get it free here:
>> http://J.mp/ingToConclusionsFree (available on iOS)
>>
>>
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