On Thu, Oct 18, 2018 at 10:12 AM, Sven R. Kunze <srkunze@mail.de> wrote:
On 18.10.18 18:49, Anders Hovmöller wrote:
If it's AND, shouldn't it be "hasinterfaces" (notice the s!)?

yeah, that would make sense.
 
Is someone proposing something here? The point I was making, is in the case of ABCs:

issubclass(a_class, an_abc)

isn't "Really" testing a subclass, but really an interface. That is - the ABC exists solely to define an interface, not provide any functionality (though there is some in there), and you can, in fact, use ABCs to provide a way to check a duck-typed class that isn't an actual subclass.

So do we need a new function that makes that clear? would it functionally be an different than issubclass with an ABC?

I honestly don't know.

Though an easy way to get the "and" behaviour -- i.e. interfaceS would be nice.

-CHB


To be sure, we are on the same page here: "interface" refers to a set of attributes of the object in question, does it?

E.g. like the __iter__ iterface. I usually don't care about the actual inheritance hierarchy but care about functionality.

One could also imagine that isinstance and issubclass taking a keyword argument for the logical operator. Maybe just something as simple as "isinstance(foo, (a, b), all=True)"

 Does AND even make sense for isinstance/issubclass?

Cheers,
Sven


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