iter jitters

[Steven Brent]

Hi folks,

In the snippet below, I'm trying to overload the __iter__ list method:

     def __iter__(self):
             print "using custom iter"
             counter = 0
             end = len(self.data) - 1
             while counter <= end:
                print self.data[counter]
                counter += 1

It pretty much works, except that the output is ugly when the while loop
falls off the end of the list:

     >>> L3 = [1,2,3,'x','y',z']

     >>> for item in L3: print item,

     using custom iter
     1
     2
     3
     x
     y
     z
     Traceback (most recent call last):
       File "mylist.py", line 38, in ?
         for item in L3:print item,
     TypeError: iter() returned non-iterator of type 'NoneType'

Oh, yeah, plus it's adding a newline at the end of each item even though 
I've got the comma there. I'm gonna keep plugging away to see if I can 
figure this out, but stuff like this makes me frustrated... Thanks a 
million.