ardief wrote:
> Hi everyone
> Here is my problem:
> I have a list that looks like this -
> [['a', '13'], ['a', '3'], ['b', '6'], ['c', '12'], ['c', '15'], ['c',
> '4'], ['d', '2'], ['e', '11'], ['e', '5'], ['e', '16'], ['e', '7']]
>
> and I would like to end up with something like this, i.e. with the
> only one list per letter:
>
> [['a', ['13' '3']], ['b', '6'], ['c', ['12', '15', '4']], ['d', '2'],
> ['e', ['11', '5', '16', '7']]]
>
> I have the feeling it's trivial, and I've scoured the group archives -
> sets might be a possibility, but I'm not sure how to operate on a list
> of lists with sets.
>
> This function also gives me what I want, more or less, but I don't
> know how to make it run until it's covered all the possibilities, if
> that makes sense...
>
> def sigh(list):
> for a in list:
> i = list.index(a)
> if a != list[-1]: ##if a is not the last one, i.e. there is a
> next one
> n = alist[i+1]
> if a[0] == n[0]:
> a.append(n[1:])
> del alist[i+1]
>
> Sorry about the lengthy message and thanks for your suggestions - I'm
> trying to learn...
>
One solution:
l=[['a', '13'], ['a', '3'], ['b', '6'], ['c', '12'], ['c', '15'], ['c','4'],
['d', '2'], ['e', '11'], ['e', '5'], ['e', '16'], ['e', '7']]
d={}
for k, v in l:
if d.has_key(k): d[k].append(v)
else: d[k]=[v]
print "d=", d
l=[x for x in d.items()]
print l
-Larry
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