Simple List division problem

Fredrik Lundh fredrik at pythonware.com
Sat Jan 12 20:33:50 CET 2008


marcstuart wrote:

> How do I divide a list into a set group of sublist's- if the list is
> not evenly dividable ?  consider this example:
> 
> x = [1,2,3,4,5,6,7,8,9,10]
> y = 3      # number of lists I want to break x into
> z = y/x
> 
> what I would like to get is 3 sublists
> 
> print z[0] = [1,2,3]
> print z[2] = [4,5,6]
> print z[3] = [7,8,9,10]
> 
> obviously not even, one list will have 4 elements, the other 2 will
> have 3.,

here's one way to do it:

# chop it up
n = len(x) / y
z = [x[i:i+n] for i in xrange(0, len(x), n)]

# if the last piece is too short, add it to one before it
if len(z[-1]) < n and len(z) > 1:
     z[-2].extend(z.pop(-1))

</F>




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