title: Is it safe to just implement __lt__ for a class that will be sorted?
body: <p>Suppose instances of my ClassA will end up in a data structure and we know sorted() will be called on it.  It's someone else's code that'll call sorted() so I can't specify a sorting function but I can implement whatever methods are appropriate on ClassA.</p>
  
  <p>It appears to me that</p>
  
  <pre><code>def __lt__(self, other):
  </code></pre>
  
  <p>is sufficient and that I don't need implement the other five or so methods (qt,eq,le,ge,ne).  </p>
  
  <p>Is this sufficient?</p>