title: for(i=0;True;i++) in python?
body: <p>Is there a more pythonic way, or at least a shorter and simpler way, to do this:</p>
  
  <pre><code>i = 1
  while True:
      res = lookup(i) # returns a value or None
      if res is None:
          break
      else:
          i += 1
          yield res
  </code></pre>