On 7/25/2019 4:27 AM, Kyle Stanley wrote:
Serhiy Storchaka wrote:
Is there any precedence of raising an exception in the equality comparison?
Does 3 == "3" returning False make more sense to you?
Personally, I don't find ``3 == "3"`` to be an equivalent comparison to
``d0.values() == d1.values()``. Generally, it makes sense when comparing two items of
different types, they are not going to be equivalent (except in cases such as ``3 ==
3.0``, but in that case they are both subtypes of numeric).
I don't know that an exception would be the best behavior to suit this situation (or for
anything using ``__eq__`` for that matter), but returning ``False`` seems to be a bit
misleading. Instead, I think that either returning the ``NotImplemented`` constant or
``None`` would provide far more useful information to the user, without the hindrance of
causing an exception. I'm leaning more favorably towards ``NotImplemented`` because it
explicitly tells the user "Hey, that equality comparison isn't implemented".
That makes things worse. Now the comparison is always true in a boolean
context. And presumably you'd want __ne__ to also return NotImplemented,
so then both __eq__ and __ne__ would be true, since bool(NotImplemented)
is True.
Eric
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