title: Unsupported operand type(s) for *: 'NoneType' and 'NoneType' (Python)
body: <p>I'm currently just toying around with defining functions and I'm getting this error. I'm just trying to make an easy function where the user inputs 2 numbers and then it multiplies them together. Also please explain what I'm doing wrong as simply as possible. (I'm a noob)</p>
  
  <pre><code>def userinput():
      while True:
          try:
              number = int(input("Number: "))
              break
          except ValueError:
              print("NOPE...")
  
  def multiply(x,y):
      z = x * y
      print(z)
  
  while True:
      x = userinput()
      y = userinput()
      multiply(x,y)
      again = input("Again? ")
      if again == "No" or again == "no":
          break
      else:
          pass
  </code></pre>