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Re: Why does 1**2**3**4**5 raise a MemoryError?

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Date Mon, 1 Apr 2013 09:28:17 +1100
Subject Re: Why does 1**2**3**4**5 raise a MemoryError?
From Chris Angelico <rosuav@gmail.com>
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On Mon, Apr 1, 2013 at 9:06 AM, Alex <foo@email.invalid> wrote:
> Dave Angel wrote:
>
>> On 03/31/2013 02:56 AM, morphex wrote:
>> > > > > 1**2
>> > 1
>> > > > > 1**2**3
>> > 1
>> > > > > 1**2**3**4
>> > 1L
>> > > > > 1**2**3**4**5
>> > Traceback (most recent call last):
>> >   File "<stdin>", line 1, in <module>
>> > MemoryError
>> > > > >
>> >
>> > Does anyone know why this raises a MemoryError?  Doesn't make sense
>> > to me.
>>
>> Perhaps you didn't realize that the expression will be done from
>> right to left.
>
> Really?
>
> The Python 3 documentation
> (http://docs.python.org/3/reference/expressions.html) says in section
> 6.14 (Evaluation order) that "Python evaluates expressions from left to
> right" (an exception being when evaluating assignments, in which case
> the RHS of the assignment is calculated first, in left-to-right order).
>
> Section 6.4 discusses the power operator specifically and does not
> contradict 6.14 except that the power operator uses right-to-left
> evaluation in the presence of unparenthesized unary operators.

http://docs.python.org/3/reference/expressions.html#operator-precedence

Opening paragraph, "... exponentiation, which groups from right to
left". It follows the obvious expectation from mathematics. (The OP is
using Python 2, but the same applies.)

ChrisA

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Thread

Why does 1**2**3**4**5 raise a MemoryError? morphex <morphex@gmail.com> - 2013-03-30 23:56 -0700
  Re: Why does 1**2**3**4**5 raise a MemoryError? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-31 07:33 +0000
    Re: Why does 1**2**3**4**5 raise a MemoryError? Dave Angel <davea@davea.name> - 2013-03-31 03:48 -0400
    Re: Why does 1**2**3**4**5 raise a MemoryError? morphex <morphex@gmail.com> - 2013-03-31 05:07 -0700
      Re: Why does 1**2**3**4**5 raise a MemoryError? Dave Angel <d@davea.name> - 2013-03-31 08:43 -0400
        Re: Why does 1**2**3**4**5 raise a MemoryError? Roy Smith <roy@panix.com> - 2013-03-31 09:15 -0400
          Re: Why does 1**2**3**4**5 raise a MemoryError? Jason Swails <jason.swails@gmail.com> - 2013-03-31 10:03 -0400
      Re: Why does 1**2**3**4**5 raise a MemoryError? Roy Smith <roy@panix.com> - 2013-03-31 09:04 -0400
      Re: Why does 1**2**3**4**5 raise a MemoryError? Tim Roberts <timr@probo.com> - 2013-04-01 21:45 -0700
        Re: Why does 1**2**3**4**5 raise a MemoryError? Chris Angelico <rosuav@gmail.com> - 2013-04-02 17:16 +1100
        Re: Why does 1**2**3**4**5 raise a MemoryError? Dan Sommers <dan@tombstonezero.net> - 2013-04-02 12:56 +0000
    Re: Why does 1**2**3**4**5 raise a MemoryError? Roy Smith <roy@panix.com> - 2013-03-31 08:59 -0400
  Re: Why does 1**2**3**4**5 raise a MemoryError? Dave Angel <davea@davea.name> - 2013-03-31 03:34 -0400
    Re: Why does 1**2**3**4**5 raise a MemoryError? "Alex" <foo@email.invalid> - 2013-03-31 22:06 +0000
      Re: Why does 1**2**3**4**5 raise a MemoryError? Chris Angelico <rosuav@gmail.com> - 2013-04-01 09:28 +1100
        Re: Why does 1**2**3**4**5 raise a MemoryError? "Alex" <foo@email.invalid> - 2013-04-01 00:39 +0000
          Re: Why does 1**2**3**4**5 raise a MemoryError? Chris Angelico <rosuav@gmail.com> - 2013-04-01 11:58 +1100
          Re: Why does 1**2**3**4**5 raise a MemoryError? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-04-01 04:16 +0000
            Re: Why does 1**2**3**4**5 raise a MemoryError? Roy Smith <roy@panix.com> - 2013-04-01 07:48 -0400
          Re: Why does 1**2**3**4**5 raise a MemoryError? Nobody <nobody@nowhere.com> - 2013-04-02 08:40 +0100
      Re: Why does 1**2**3**4**5 raise a MemoryError? Chris Angelico <rosuav@gmail.com> - 2013-04-01 09:32 +1100
      Re: Why does 1**2**3**4**5 raise a MemoryError? Dave Angel <davea@davea.name> - 2013-03-31 18:34 -0400

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