title: Modifying function arguments
body: <p>Sorry if this is a dumb question, but I've looked for a while and not really found the answer.</p>
  
  <p>If I'm writing a python function, for example:</p>
  
  <pre><code>def function(in1, in2):
      in1=in1+1
      in2=in2+1
  </code></pre>
  
  <p>How do I make these changes stick?</p>
  
  <p>I know why they dont, this has been addressed in many answers, but I couldn't find an answer to the question of how to actually make them do so. Without returning values or making some sort of class, is there really no way for a function to operate on its arguments in a global sense?</p>
  
  <p>I also want these variables to not be global themselves, as in I want to be able to do this:</p>
  
  <pre><code>a=1
  b=2
  c=3
  d=4
  function(a,b)
  function(c,d)
  </code></pre>
  
  <p>Is this just wishful thinking?</p>