hello, thanks to all who replied to my post (2005-01-21) - (i can not post inside the original thread as i get "Unable to retrieve message [EMAIL PROTECTED]" from googlenews :(
> Do you mean: > [1,2], [2,3], [3,4], [1,2,3], [2,3,4], [1,3,4] > (E.g. all elements in the power set except the empty set, the sets with > one element and the sets with all elements.) > Otherwise, please describe your desired sets in verbal - I cannot see > the point. yes it was my wishes, but having the others empty, one and all elements wasn't a big trouble, actually i wanted to understand more generators. > Here is an (untested) variant that accepts any iterable while trying to > remain memory-efficient. This makes it necessary to shuffle the order of > the output a bit. > from itertools import tee, islice > def gen(iterable, start, end): > it = iter(iterable) > while True: > it, a = tee(it) > a = tuple(islice(a, end-1)) > for sz in xrange(start, len(a)+1): > yield a[:sz] > it.next() > > if __name__ == "__main__": > print list(gen(range(1, 5), 2, 4)) please, this one looks interesting, could you explain a bit how it works and why it "remain memory-efficient" ? thanks, -- http://mail.python.org/mailman/listinfo/python-list
