title: Check if an object is in a sorted list
body: <p>What's the easiest way to check weather an object is in a sorted list?
  I have found bisect, but that only finds the insertion points.
  Sure this index could then be used to check if the object exists in the list.
  But is there a easier way?</p>
  
  <p>Something similar to the "in" command? Returning a True/False but for sorted lists?</p>