title: Automatically generating Python type annotations?
body: <p>I'm retrofitting some old Python code to add PyType annotations.  I'm doing this mechanically, by adding print statements to the top of each function</p>
  
  <pre><code>def f(a, b):
      print("type a:", type(a))
      print("type b:", type(b))
  </code></pre>
  
  <p>and updating accordingly.</p>
  
  <p>Is there anything which can help automate this process?</p>