On 01/07/2018 04:31 PM, breamore...@gmail.com wrote:
On Monday, January 8, 2018 at 12:02:09 AM UTC, Ethan Furman wrote:
On 01/07/2018 12:33 PM, Chris Angelico wrote:
On Mon, Jan 8, 2018 at 7:13 AM, Thomas Jollans wrote:
On 07/01/18 20:55, Chris Angelico wrote:
Under what circumstances would you want "x != y" to be different from
"not (x == y)" ?
In numpy, __eq__ and __ne__ do not, in general, return bools.
a = np.array([1,2,3,4])
b = np.array([0,2,0,4])
a == b
array([False, True, False, True], dtype=bool)
a != b
array([ True, False, True, False], dtype=bool)
Thanks, that's the kind of example I was looking for. Though numpy
doesn't drive the core language development much, so the obvious next
question is: was this why __ne__ was implemented, or was there some
other reason? This example shows how it can be useful, but not why it
exists.
Actually, I think it is why it exists. If I recall correctly, the addition of
the six comparative operators* was added
at the behest of the scientific/numerical community.
--
~Ethan~
* Yeah, I can't remember the cool name for those six operators at the moment.
:(
The six rich comparison methods were added to 2.1 as a result of PEP 207, which
confirms that you're correct, they were added at the request of the numpyites.
Cool, thanks for tracking that down!
--
~Ethan~
--
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