title: How to select cells greater than a value in a multi-index Pandas dataframe?
body: <p>Try 1:</p>
  
  <p><code>df[ df &gt; 1.0 ]</code> : this returned all cells in <code>NAN</code>.</p>
  
  <p>Try2:</p>
  
  <p><code>df.loc[ df &gt; 1.0 ]</code> : this returned <code>KeyError: 0</code></p>
  
  <p><code>df[df['A']&gt; 1.0]</code> : this works - But I want to apply the filter condition to all columns.</p>