Dave Dean wrote:
> Hi all,
> I'm looking for a way to iterate through a list, two (or more) items at a
> time. Basically...
>
> myList = [1,2,3,4,5,6]
>
> I'd like to be able to pull out two items at a time - simple examples would
> be:
> Create this output:
> 1 2
> 3 4
> 5 6
>
> Create this list:
> [(1,2), (3,4), (5,6)]
>
A "padding generator" version:
def chunk( seq, size, pad=None ):
'''
Slice a list into consecutive disjoint 'chunks' of
length equal to size. The last chunk is padded if necessary.
>>> list(chunk(range(1,10),3))
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> list(chunk(range(1,9),3))
[[1, 2, 3], [4, 5, 6], [7, 8, None]]
>>> list(chunk(range(1,8),3))
[[1, 2, 3], [4, 5, 6], [7, None, None]]
>>> list(chunk(range(1,10),1))
[[1], [2], [3], [4], [5], [6], [7], [8], [9]]
>>> list(chunk(range(1,10),9))
[[1, 2, 3, 4, 5, 6, 7, 8, 9]]
>>> for X in chunk([],3): print X
>>>
'''
n = len(seq)
mod = n % size
for i in xrange(0, n-mod, size):
yield seq[i:i+size]
if mod:
padding = [pad] * (size-mod)
yield seq[-mod:] + padding
------------------------------------------------------------------
Gerard
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