title: Python Pandas Distance matrix using jaccard similarity
body: <p>I have implemented a function to construct a distance matrix using the jaccard similarity:</p>
  
  <pre><code>import pandas as pd
  entries = [
      {'id':'1', 'category1':'100', 'category2': '0', 'category3':'100'},
      {'id':'2', 'category1':'100', 'category2': '0', 'category3':'100'},
      {'id':'3', 'category1':'0', 'category2': '100', 'category3':'100'},
      {'id':'4', 'category1':'100', 'category2': '100', 'category3':'100'},
      {'id':'5', 'category1':'100', 'category2': '0', 'category3':'100'}
             ]
  df = pd.DataFrame(entries)
  </code></pre>
  
  <p>and the distance matrix with scipy</p>
  
  <pre><code>from scipy.spatial.distance import squareform
  from scipy.spatial.distance import pdist, jaccard
  
  res = pdist(df[['category1','category2','category3']], 'jaccard')
  squareform(res)
  distance = pd.DataFrame(squareform(res), index=df.index, columns= df.index)
  </code></pre>
  
  <p>The problem is that my result looks like this which seems to be false:</p>
  
  <p><a href="https://i.stack.imgur.com/wPsJW.png" rel="noreferrer"><img src="https://i.stack.imgur.com/wPsJW.png" alt="enter image description here"></a></p>
  
  <p>What am i missing? The similarity of 0 and 1 have to be maximum for example and the other values seem wrong too</p>