title: Underscore after a variable name in Python
body: <p>I am deciphering someone else's code and I see the following:</p>
  
  <pre><code>def get_set_string(set_):
       if PY3:
           return str(set_)
       else:
           return str(set_)
  </code></pre>
  
  <p>Does the underscore AFTER the variable mean anything or is this just a part of the variable's name and means nothing?</p>