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Sorting (deeply) nested lists

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  Sorting (deeply) nested lists mamboknave@gmail.com - 2013-03-02 09:18 -0800
    Re: Sorting (deeply) nested lists Peter Otten <__peter__@web.de> - 2013-03-02 18:36 +0100
      Re: Sorting (deeply) nested lists mamboknave@gmail.com - 2013-03-02 09:49 -0800
      Re: Sorting (deeply) nested lists mamboknave@gmail.com - 2013-03-02 09:49 -0800

#40338 — Sorting (deeply) nested lists

I cannot resolve this on my own. Need help, please...

nestedTuples = [
[ (L0t0e0, L0t0e1, L0t0e2), (L0t1e0, 2, L0t1e2), (L0t2e0, L0t2e1, L0t2e2) ],
[ (L1t0e0, L1t0e1, L1t0e2), (L1t1e0, 0, L1t1e2), (L1t2e0, L1t2e1, L1t2e2) ],
[ (L2t0e0, L2t0e1, L2t0e2), (L2t1e0, 1, L2t1e2), (L2t2e0, L2t2e1, L2t2e2) ] ]

With LNtXeY I mean the element Y in the tuple X of the list N.

How can I sort nestedTuples by, say, the 2nd element in the 2nd tuple of each list?

The above should get sorted as :

nestedTuples = [
[ (L1t0e0, L1t0e1, L1t0e2), (L1t1e0, 0, L1t1e2), (L1t2e0, L1t2e1, L1t2e2) ],
[ (L2t0e0, L2t0e1, L2t0e2), (L2t1e0, 1, L2t1e2), (L2t2e0, L2t2e1, L2t2e2) ],
[ (L0t0e0, L0t0e1, L0t0e2), (L0t1e0, 2, L0t1e2), (L0t2e0, L0t2e1, L0t2e2) ] ]

Thanks so much!!

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#40343

mamboknave@gmail.com wrote:

> I cannot resolve this on my own. Need help, please...
> 
> nestedTuples = [
> [ (L0t0e0, L0t0e1, L0t0e2), (L0t1e0, 2, L0t1e2), (L0t2e0, L0t2e1, L0t2e2)
> [ ], (L1t0e0, L1t0e1, L1t0e2), (L1t1e0, 0, L1t1e2), (L1t2e0, L1t2e1,
> [ L1t2e2) ], (L2t0e0, L2t0e1, L2t0e2), (L2t1e0, 1, L2t1e2), (L2t2e0,
> [ L2t2e1, L2t2e2) ] ]
> 
> With LNtXeY I mean the element Y in the tuple X of the list N.
> 
> How can I sort nestedTuples by, say, the 2nd element in the 2nd tuple of
> each list?

def getkey(item):
    return item[1][1]
namedTuples.sort(key=getkey)

You can also write this as

namedTuples.sort(key=lambda item: item[1][1])

> The above should get sorted as :
> 
> nestedTuples = [
> [ (L1t0e0, L1t0e1, L1t0e2), (L1t1e0, 0, L1t1e2), (L1t2e0, L1t2e1, L1t2e2)
> [ ], (L2t0e0, L2t0e1, L2t0e2), (L2t1e0, 1, L2t1e2), (L2t2e0, L2t2e1,
> [ L2t2e2) ], (L0t0e0, L0t0e1, L0t0e2), (L0t1e0, 2, L0t1e2), (L0t2e0,
> [ L0t2e1, L0t2e2) ] ]

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#40346

On Saturday, March 2, 2013 9:36:43 AM UTC-8, Peter Otten wrote:
>
> You can also write this as
> 
> namedTuples.sort(key=lambda item: item[1][1])
>

That's exactly what I did before and got "IndexError: list index out of range".

So, I thought my lambda was wrong and posted here.

Now, having seen you reply, I dug deeper and... of course I had IndexError: the list was horribly empty!

Thanks so much for replying so quickly, Peter!

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#40347

On Saturday, March 2, 2013 9:36:43 AM UTC-8, Peter Otten wrote:
>
> You can also write this as
> 
> namedTuples.sort(key=lambda item: item[1][1])
>

That's exactly what I did before and got "IndexError: list index out of range".

So, I thought my lambda was wrong and posted here.

Now, having seen you reply, I dug deeper and... of course I had IndexError: the list was horribly empty!

Thanks so much for replying so quickly, Peter!

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