title: What's a standard way to do a no-op in python?
body: <p>I often find myself writing if / elif / else constructs in python, and I want to include options which can occur, but for which the corresponding action is to do nothing. I realise I could just exclude those if statements, but for readability I find it helps to include them all, so that if you are looking through the code you can see what happens as a result of each option. How do I code the no-op? Currently, I'm doing it like this:</p>
  
  <pre><code>no_op = 0
  
  if x == 0:
      y = 2 * a
  elif x == 1:
      z = 3 * b
  elif x == 3:
      no_op
  </code></pre>
  
  <p>(The code is actually quite a bit longer than that, and more complicated. This is just to illustrate the structure).</p>
  
  <p>I don't like using a variable as a no-op, but it's the neatest way I could think of. Is there a better way?</p>