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In-Reply-To: <20130607213239.3e39a448@bigbox.christie.dr>
References: <20130607213239.3e39a448@bigbox.christie.dr>
Date: Sat, 8 Jun 2013 13:59:01 +1000
Subject: Re: Idiomatic Python for incrementing pairs
From: Chris Angelico <rosuav@gmail.com>
To: python-list@python.org
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Xref: csiph.com comp.lang.python:47361

On Sat, Jun 8, 2013 at 12:32 PM, Tim Chase
<python.list@tim.thechases.com> wrote:
>   def calculate(params):
>     a = b = 0
>     if some_calculation(params):
>       a += 1
>     if other_calculation(params):
>       b += 1
>     return (a, b)
>
>   alpha = beta = 0
>   temp_a, temp_b = calculate(...)
>   alpha += temp_a
>   beta += temp_b
>
> Is there a better way to do this without holding each temporary
> result before using it to increment?

Can you pass the function a list with the appropriate values in them,
and have it return them via that?

  def calculate(params, sums):
    if some_calculation(params):
      sums[0] += 1
    if other_calculation(params):
      sums[1] += 1

  sums = [0, 0]
  calculate(..., sums)

Or use a dictionary if you'd rather they have names, either way.

ChrisA