How to emulate a do-while loop?

I need to emulate a do-while loop in a Python program. Unfortunately, the following straightforward code does not work:

list_of_ints = [ 1, 2, 3 ]
iterator = list_of_ints.__iter__()
element = None

while True:
  if element:
    print element

  try:
    element = iterator.next()
  except StopIteration:
    break

print "done"

Instead of "1,2,3,done", it prints the following output:

[stdout:]1
[stdout:]2
[stdout:]3
None['Traceback (most recent call last):
', '  File "test_python.py", line 8, in 
    s = i.next()
', 'StopIteration
']

What can I do in order to catch the 'stop iteration' exception and break a while loop properly?

An example of why such a thing may be needed is shown below as pseudocode.

State machine:

s = ""
while True :
  if state is STATE_CODE :
    if "//" in s :
      tokens.add( TOKEN_COMMENT, s.split( "//" )[1] )
      state = STATE_COMMENT
    else :
      tokens.add( TOKEN_CODE, s )
  if state is STATE_COMMENT :
    if "//" in s :
      tokens.append( TOKEN_COMMENT, s.split( "//" )[1] )
    else
      state = STATE_CODE
      # Re-evaluate same line
      continue
  try :
    s = i.next()
  except StopIteration :
    break