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Re: Operator precedence problem

From Random832 <random832@fastmail.com>
Newsgroups comp.lang.python
Subject Re: Operator precedence problem
Date 2016-06-05 13:19 -0400
Message-ID <mailman.11.1465147176.2306.python-list@python.org> (permalink)
References <816c651a-d0ae-4e23-a5b2-72a8f7398468@googlegroups.com> <1465147173.2666461.628499265.4DB6AD8F@webmail.messagingengine.com>

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On Sun, Jun 5, 2016, at 02:53, ICT Ezy wrote:
> >>> 2 ** 3 ** 2 
> Answer is 512
> Why not 64?
> Order is right-left or left-right?

You're mixing up order of evaluation with operator associativity. The **
operator is right-to-left associative, this means x ** y ** z == x ** (y
** z). Evaluation is left to right, where it matters [i.e. if one or
more of the elements here were an expression with side effects]: first x
is evaluated, then tmp=y**z, then x**tmp. These are two entirely
different concepts.

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Operator precedence problem ICT Ezy <ictezy@gmail.com> - 2016-06-04 23:53 -0700
  Re: Operator precedence problem Peter Otten <__peter__@web.de> - 2016-06-05 09:35 +0200
    Re: Operator precedence problem ICT Ezy <ictezy@gmail.com> - 2016-06-05 08:05 -0700
      Re: Operator precedence problem Uri Even-Chen <uri@speedy.net> - 2016-06-05 19:05 +0300
        Re: Operator precedence problem ICT Ezy <ictezy@gmail.com> - 2016-06-05 20:24 -0700
        Re: Operator precedence problem Lawrence D’Oliveiro <lawrencedo99@gmail.com> - 2016-06-05 22:46 -0700
          Re: Operator precedence problem Random832 <random832@fastmail.com> - 2016-06-06 09:57 -0400
            Re: Operator precedence problem Marko Rauhamaa <marko@pacujo.net> - 2016-06-06 17:22 +0300
              Re: Operator precedence problem Random832 <random832@fastmail.com> - 2016-06-06 10:35 -0400
                Re: Operator precedence problem Marko Rauhamaa <marko@pacujo.net> - 2016-06-06 17:55 +0300
              Re: Operator precedence problem Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-06-06 15:03 +0000
                Re: Operator precedence problem Marko Rauhamaa <marko@pacujo.net> - 2016-06-06 18:22 +0300
                Re: Operator precedence problem Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-06-06 15:27 +0000
                Re: Operator precedence problem Chris Angelico <rosuav@gmail.com> - 2016-06-07 01:57 +1000
                Re: Operator precedence problem Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-06-06 16:05 +0000
                Re: Operator precedence problem Chris Angelico <rosuav@gmail.com> - 2016-06-07 02:21 +1000
                Re: Operator precedence problem Jon Ribbens <jon+usenet@unequivocal.co.uk> - 2016-06-06 17:02 +0000
                Re: Operator precedence problem Grant Edwards <grant.b.edwards@gmail.com> - 2016-06-06 16:51 +0000
              Re: Operator precedence problem Peter Otten <__peter__@web.de> - 2016-06-06 18:38 +0200
            Re: Operator precedence problem Steven D'Aprano <steve@pearwood.info> - 2016-06-07 03:07 +1000
              Re: Operator precedence problem Random832 <random832@fastmail.com> - 2016-06-06 14:44 -0400
                Re: Operator precedence problem Marko Rauhamaa <marko@pacujo.net> - 2016-06-06 21:49 +0300
              Re: Operator precedence problem MRAB <python@mrabarnett.plus.com> - 2016-06-06 20:17 +0100
                Re: Operator precedence problem Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-06-07 11:27 +1200
            Re: Operator precedence problem Rustom Mody <rustompmody@gmail.com> - 2016-06-06 10:14 -0700
              Re: Operator precedence problem Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-06-06 21:09 +0100
      Re: Operator precedence problem Michael Torrie <torriem@gmail.com> - 2016-06-05 17:47 -0600
        Re: Operator precedence problem ICT Ezy <ictezy@gmail.com> - 2016-06-05 20:23 -0700
  Re: Operator precedence problem Chris Angelico <rosuav@gmail.com> - 2016-06-06 02:24 +1000
    Re: Operator precedence problem Peter Pearson <pkpearson@nowhere.invalid> - 2016-06-06 16:58 +0000
      Re: Operator precedence problem Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2016-06-07 11:21 +1200
  Re: Operator precedence problem Random832 <random832@fastmail.com> - 2016-06-05 13:19 -0400
    Re: Operator precedence problem ICT Ezy <ictezy@gmail.com> - 2016-06-05 20:23 -0700
  Re: Operator precedence problem Gary Herron <gherron@digipen.edu> - 2016-06-05 00:04 -0700

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