> for example:
> a = [1,2,3,4,5,6,7,8,9,10] #Although not necessarily in order
>
> def cmp(i,j): #to be defined in this thread.
Well, if you're willing to give up doing it in a cmp() method,
you can do it as such:
>>> a.sort()
>>> chunk_size = 3
>>> [a[i::chunk_size] for i in range(chunk_size)]
[[1, 4, 7, 10], [2, 5, 8], [3, 6, 9]]
If you need it in a flat list, rather than as a list of
chunk_size lists (which are handy for iterating over in many
cases), there are ways of obtaining it, such as the hackish
>>> sum([a[i::chunk_size] for i in range(chunk_size)], [])
[1, 4, 7, 10, 2, 5, 8, 3, 6, 9]
There are likely good recipes for flattening a list. I just
happen not to have any at my fingertips.
I'm not sure it's possible to do in a cmp() method, given that it
requires apriori knowledge of the dataset (are the numbers
contiguous?). Unless, of course, you have such a list...
However, as a benefit, this method should work no matter what the
list contains, as long as they're comparable to each other for an
initial sorting:
>>> a = [chr(ord('a') + i) for i in range(10)]
>>> # a.sort() if it were needed
>>> a
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
>>> sum([a[i::chunk_size] for i in range(chunk_size)], [])
['a', 'd', 'g', 'j', 'b', 'e', 'h', 'c', 'f', 'i']
-tkc
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