title: pandas filter rows by two column values with case insenstive
body: <p>I have a simple dataframe as follows:</p>
  
  <pre><code>Last Known Date ConfigredValue  ReferenceValue
  0   24-Jun-17   False   FALSE
  1   25-Jun-17   FALSE   FALSE
  2   26-Jun-17   TRUE    FALSE
  3   27-Jun-17   FALSE   FALSE
  4   28-Jun-17   false   FALSE
  </code></pre>
  
  <p>If I do the following command</p>
  
  <p><strong><code>df=df[df['ConfigredValue']!=dfs['ReferenceValue']]</code></strong></p>
  
  <p>then I get as below</p>
  
  <pre><code>0   24-Jun-17   False   FALSE
  2   26-Jun-17   TRUE    FALSE
  4   28-Jun-17   false   FALSE
  </code></pre>
  
  <p>But I want the filter with case insensitive (case=False)</p>
  
  <p>I want following output:</p>
  
  <pre><code>2   26-Jun-17   TRUE    FALSE
  </code></pre>
  
  <p>Please suggest, how to get filtered case insensitive data(case=false)</p>