title: How do I block python RuntimeWarning from printing to the terminal?
body: <p>I have some python code that, at some point, takes the axis means of a reasonably sparse array with nans in. Every time I run the code it raises a <code>RuntimeWarning</code>. </p>
  
  <p>I know what's causing the warning, it's intentional, and it doesn't affect the output. It is, however, quite irritating to be presented with the warning every time I run the program - so, is there a cheap and nasty way to prevent them from being printed to the terminal?</p>