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Date: Thu, 18 Aug 2011 07:45:10 -0500
From: Tim Chase <python.list@tim.thechases.com>
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Subject: Re: lists and for loops
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:11746

On 08/18/2011 07:22 AM, Mark Niemczyk wrote:
> Or, using list comprehension.
>
>>>> numbers = [1, 2, 3, 4, 5]
>>>> numbers = [n + 5 for n in numbers]
>>>> numbers
> [6, 7, 8, 9, 10]

Or, if you want it in-place:

   numbers[:] = [n+5 for n in numbers]

which makes a difference if you have another reference to numbers:

 >>> numbers = [1,2,3,4,5]
 >>> digits = numbers
 >>> numbers = [n+5 for n in numbers]
 >>> numbers, digits
([6, 7, 8, 9, 10], [1, 2, 3, 4, 5])
 >>> numbers = [1,2,3,4,5]
 >>> digits = numbers
 >>> numbers[:] = [n+5 for n in numbers]
 >>> numbers, digits
([6, 7, 8, 9, 10], [6, 7, 8, 9, 10])

-tkc