title: Jaccard Distance calculation using pdist in scipy
body: <pre><code>import scipy.spatial.distance as dist
  
  Y=[[1,2,3],[2,3,4]]
  
  Q=dist.pdist(Y,'jaccard')
  
  print Q
  </code></pre>
  
  <p>The following snippet gives jaccard distance as <code>1</code> while it should be <code>0.5</code>.
  On the other hand if <code>Y=[[1,2,3],[4,2,3]]</code> i.e if ordering is changed output is 0.33. But jaccard distance is independent of order of elements. Can you suggest how to resolve this issue here?</p>