title: What type signature do generators have in Python?
body: <p>Given that the new Python 3.5 allows type hinting with type signatures I want to use the new feature, but I don't know how to fully annotate a function with the following structure:</p>
  
  <pre><code>def yieldMoreIfA(text:str):
      if text == "A":
          yield text
          yield text
          return
      else:
          yield text
          return
  </code></pre>
  
  <p>What's the correct signature?</p>