Re: list mutability (very basic question)
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- Subject: [mg131709] Re: list mutability (very basic question)
- From: Alan G Isaac <alan.isaac at gmail.com>
- Date: Sun, 22 Sep 2013 02:47:01 -0400 (EDT)
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On 9/21/2013 10:15 AM, Bob Hanlon wrote: > Attributes[Set] > {HoldFirst, Protected, SequenceHold} Thanks, but I'm still unclear: why does ``{0}[[1]]=1`` raise an error? As a point of reference for my confusion, Python behaves in a way I find more intuitive: ``[0,1][1]=0`` does not raise an error. (This becomes an interesting difference when we get to argument passing in Mathematica, where HoldFirst becomes useful as a way to allow "in place" modification.) Back to Mathematica, am I understanding correctly that after ``Set[Part[x,1],1])`` that x still references the same location in memory? How can I easily see that? (E.g., in Python, I would us the ``id`` function.) Thanks, Alan Isaac
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- list mutability (very basic question)
- From: Alan <alan.isaac@gmail.com>
- list mutability (very basic question)