list: from 2 to 3 dimensions..looking for a nice way

[Mike C. Fletcher]

You want to collect those items in a with equal values for item[1], so:

 >>> c = {}
 >>> for item in a:
...     c.setdefault(item[1],[]).append( item )
...    
 >>> c.values()
[[[1, 'house'], [2, 'house']], [[3, 'garden']]]

HTH,
Mike

sven wrote:

>I've got a nested list-> 
>a = [[1,'house'],[2,'house'],[3,'garden']] 
>
>
>and I want to get one level deeper  with the lists having the same value in 
>index value 1
>
>b =[[[1, 'house'], [2, 'house']], [[3, 'garten']]]
>
>
>I' achieving this with an ugly syntax:
>
>a = [[1,'house'],[2,'house'],[3,'garden']]
>b = [[]]
>b[0].append(a.pop(0))
> 
>for id in range(len(a)):
>	if(b[-1][0][1]==a[id][1]):
>		b[-1].append(a[id])
>	else:
>		b.append([a[id]])
>
>What is the pythonic way to do this?
>Thanks for any insight
>  
>

-- 
_______________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://members.rogers.com/mcfletch/