title: How to restore a builtin that I overwrote by accident?
body: <p>I accidentally overwrote <code>set</code> by using it as a variable name in an interactive python session - is there any way that I can get access to the original <code>set</code> function without just restarting my session? </p>
  
  <p>(I have so much stuff in that session that I'd rather not have to do that, although of course I can if necessary.)</p>