title: Passing values from function to function in JES/Jython
body: <p>I am learning Jython using a program called JES, and I am having trouble understanding how to return values from a function that can be used in another function.</p>
  
  <p>For example:</p>
  
  <pre><code>def driver():
    picture = makePicture(pickAFile())
    input(picture)
    changeRed(picture, reduceRedAmount)
  
  def input(picture):
    redReduceAmount = requestInteger("How much should I reduce red by?")
    return redReduceAmount
  def changeRed(picture, reduceRedAmount):
    for p in getPixels(picture):
      value=getRed(p)
      setRed(p,value*0.9)
  </code></pre>
  
  <p>I want to be able to just run the driver function in the command area, and have that function include the other functions.  I understand that results in functions are local and don't pass through, but I though that if you use 'return' then it stores that value for later use.  Am I on the wrong track here?  Surely there is a way to pass information between functions?</p>