[Tutor] design of Point class

[bob gailer]

  I am happier with this:

class PointND(list, object):

   def __init__(self, *a_list):
     super(PointND, self).__init__(a_list)
     self.maxIndex = len(self) - 1

   def getSet(ix, attName):
     msg = "'%s' object has no attribute '%s'" % (p.__class__.__name__, 
attName)
     def get(self):
       if self.maxIndex < ix:
         raise AttributeError, msg
       return self[ix]
     def set(self, value):
       if self.maxIndex < ix:
         raise AttributeError, msg
       self[ix] = value
     return property(get, set)

   x = getSet(0, 'x')
   y = getSet(1, 'y')
   z = getSet(2, 'z')

p = PointND(1,2,3)
assert (p.x, p.y, p.z) == (1, 2, 3)
p.x = 6; p.y = 9; p.z = 5
assert (p.x, p.y, p.z) == (6, 9, 5)

try:
   p = PointND(1,2)
   p.z = 3
except AttributeError:
   print 'Passed all tests'



-- 
Bob Gailer
919-636-4239
Chapel Hill NC