On Mon, 13 May 2013 05:23:16 +0600, Mr. Joe wrote:
> I seem to stumble upon a situation where "!=" operator misbehaves in
> python2.x. Not sure if it's my misunderstanding or a bug in python
> implementation. Here's a demo code to reproduce the behavior -
> """
> # -*- coding: utf-8 -*-
> from __future__ import unicode_literals, print_function
>
> class DemoClass(object):
> def __init__(self, val):
> self.val = val
>
> def __eq__(self, other):
> return self.val == other.val
>
> x = DemoClass('a')
> y = DemoClass('a')
>
> print("x == y: {0}".format(x == y))
> print("x != y: {0}".format(x != y))
> print("not x == y: {0}".format(not x == y))
> """
>
> In python3, the output is as expected:
> """
> x == y: True x != y: False not x == y: False """
>
> In python2.7.3, the output is:
> """
> x == y: True x != y: True not x == y: False """
> Which is not correct!!
>
> Thanks in advance for clarifications.
> Regards,
> TB
this looks to me like an issue with operator precidence
you code is evaluating as (Not x) == y
rather than not (x == y)
why the difference between 2.7 & 3.X is beyond my knowledge of the
language
The other explanations seem to detail things at low level but it is all
Greek to me
--
Nice guys finish last.
-- Leo Durocher
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