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Groups > comp.lang.python > #78861

Re: operator module functions

From Terry Reedy <tjreedy@udel.edu>
Subject Re: operator module functions
Date 2014-10-08 18:46 -0400
References (4 earlier) <543592AE.80807@stoneleaf.us> <1412797764.3704154.176743089.32D63D13@webmail.messagingengine.com> <54359623.8060307@stoneleaf.us> <1412803417.3733140.176776081.0B98584A@webmail.messagingengine.com> <5435B14C.9020907@stoneleaf.us>
Newsgroups comp.lang.python
Message-ID <mailman.14698.1412808386.18130.python-list@python.org> (permalink)

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On 10/8/2014 5:49 PM, Ethan Furman wrote:
> [redirecting back to the list]

>>>> I'm not sure what situation you would have to type them (as opposed to
>>>> simply a + b) that the operator module would help with.
>>>
>>> unittest springs to mind:
>>>
>>>     self.assertRaises(TypeError, op.add, obj1, obj2)
>>
>> Er, my point is, that is not a situation where you would be able to use
>> obj1.__add__ - you'd have to use the operator module *anyway*, and
>> therefore aren't using it just to get the convenience of a non-dunder
>> name.
>
>   self.assertRaises(TypeError, lambda x, y: x+y, obj1, obj2)

That works, but is a bit harder to type (given the import), more 
confusing to read (the extra ',' that does *not* delimit an argument) 
and adds an extra layer to the call stack with each call.  The extra 
layer *could* make a difference in recursion.

-- 
Terry Jan Reedy

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Thread

operator module functions Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-08 12:41 +1100
  Re: operator module functions Terry Reedy <tjreedy@udel.edu> - 2014-10-08 02:28 -0400
  Re: operator module functions marco.nawijn@colosso.nl - 2014-10-08 01:46 -0700
    Re: operator module functions Chris Angelico <rosuav@gmail.com> - 2014-10-08 20:32 +1100
      Re: operator module functions Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2014-10-09 10:37 +1300
        Re: operator module functions Chris Angelico <rosuav@gmail.com> - 2014-10-09 09:30 +1100
        Re: operator module functions Chris Kaynor <ckaynor@zindagigames.com> - 2014-10-08 15:40 -0700
    Re: operator module functions Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-10-08 21:57 +1100
      Re: operator module functions Terry Reedy <tjreedy@udel.edu> - 2014-10-08 15:09 -0400
      Re: operator module functions Ethan Furman <ethan@stoneleaf.us> - 2014-10-08 12:38 -0700
      Re: operator module functions random832@fastmail.us - 2014-10-08 15:49 -0400
      Re: operator module functions Gelonida N <gelonida@gmail.com> - 2014-10-08 23:05 +0200
      Re: operator module functions Ian Kelly <ian.g.kelly@gmail.com> - 2014-10-08 15:23 -0600
      Re: operator module functions Ethan Furman <ethan@stoneleaf.us> - 2014-10-08 14:49 -0700
      Re: operator module functions Chris Kaynor <ckaynor@zindagigames.com> - 2014-10-08 14:21 -0700
      Re: operator module functions Ben Finney <ben+python@benfinney.id.au> - 2014-10-09 08:57 +1100
      Re: operator module functions Terry Reedy <tjreedy@udel.edu> - 2014-10-08 18:46 -0400
      Re: operator module functions Ethan Furman <ethan@stoneleaf.us> - 2014-10-08 16:35 -0700
      Re: operator module functions Ned Batchelder <ned@nedbatchelder.com> - 2014-10-08 21:41 -0400

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