Neal Becker <ndbeck...@gmail.com> wrote:
> Is there any canned iterator adaptor that will
>
> transform:
> in = [1,2,3....]
>
> into:
> out = [(1,2,3,4), (5,6,7,8),...]
>
> That is, each time next() is called, a tuple of the next N items is
> returned.
This is my best effort... not using itertools as my brain doesn't seem
to work that way!
class Grouper(object):
def __init__(self, n, i):
self.n = n
self.i = iter(i)
def __iter__(self):
while True:
out = tuple(self.i.next() for _ in xrange(self.n))
if not out:
break
yield out
g = Grouper(5, xrange(20))
print list(g)
g = Grouper(4, xrange(19))
print list(g)
Which produces
[(0, 1, 2, 3, 4), (5, 6, 7, 8, 9), (10, 11, 12, 13, 14), (15, 16, 17, 18, 19)]
[(0, 1, 2, 3), (4, 5, 6, 7), (8, 9, 10, 11), (12, 13, 14, 15), (16, 17, 18)]
--
Nick Craig-Wood <n...@craig-wood.com> -- http://www.craig-wood.com/nick
--
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