> >>> alist = range(3) > >>> for i in xrange(len(alist)): > ... for j in xrange(i+1,len(alist)): > ... print i,j,alist[i],alist[j] > ... > 0 1 0 1 > 0 2 0 2 > 1 2 1 2 > >>> > > > Is there a way to do this without using indexes?
The following works for me, replicating your code, >>> alist = range(3) >>> for i, itemA in enumerate(alist): ... for j, itemB in enumerate(alist[i+1:]): ... print i,j+i+1,itemA, itemB ... 0 1 0 1 0 2 0 2 1 2 1 2 and is swappable if your alist has other values in it too: >>> alist = ['dog', 'cat', 'mouse'] >>> for i, itemA in enumerate(alist): ... for j, itemB in enumerate(alist[i+1:]): ... print i,j+i+1,itemA, itemB ... 0 1 dog cat 0 2 dog mouse 1 2 cat mouse However, if your list only has those range() values in it, there's nothing wrong with doing something like >>> for i in alist: ... for j in alist[i+1:]: ... print i,j,i,j ... It looks like you're trying to do permutations/combinations of things, in which case you might also find this helpful: http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/190465 -tim -- http://mail.python.org/mailman/listinfo/python-list
