True is True / False is False?

[Tim Chase]

On 2020-07-22 11:54, Oscar Benjamin wrote:
>> On Wed, Jul 22, 2020 at 11:04 AM Tim Chase wrote:  
>>> reading through the language specs and didn't encounter
>>> anything about booleans returned from comparisons-operators,
>>> guaranteeing that they always return The One True and The One
>>> False.  
>>
>> That said, though, a comparison isn't required to return a bool.
>> If it *does* return a bool, it has to be one of those exact two,
>> but it could return anything it chooses. But for built-in types
>> and most user-defined types, you will indeed get a bool.  
> 
> I'm not sure if this is relevant to the question but thought I'd
> mention concrete examples. A numpy array will return non-bool for
> both of the mentioned operators

that is indeed a helpful data-point.  Do you know of any similar
example in the standard library of things where comparison-operators
return something other than True or False (or None)?

Thanks,

-tkc