recursively change values in list of lists

[Medardo Rodriguez (Merchise Group)]

On Sun, Aug 24, 2008 at 10:17 AM, Carson Farmer <carson.farmer at gmail.com> wrote:
> So in the end, the only thing that should be changed is the values,
> not the lists themselves... clear as mud?
>
> Any hints, and/or suggestions are greatly appreciated,

You gave the solution yourself.

I don't know if your inner polygons can contain lines and polygons, or
only lines, so:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright (c) 2008 Medardo Rodriguez (Merchise Group)
#
# This is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License (GPL) as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# :)

def MoveDelta(target, dx, dy):
   for item in target:
       if isinstance(item[0], list):    # is item a polygon?
           MoveDelta(item, dx, dy)      # Recursive version
       else:
           assert len(item) == 2        # make sure that it is a point
           item[0] += dx
           item[1] += dy

if __name__ == '__main__':
   sample = [[[1, 2], [3, 4]], [[[7, 8], [10, 20]], [5, 6]]]
   print 'Original:', sample
   MoveDelta(sample, 10, 100)
   print 'Result:', sample

# Regards