title: Pandas & filtering
body: <p>I have an error </p>
  
  <p><code>**'ufunc 'bitwise_and' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe'**</code></p>
  
  <p>when I am attempting to filter by my code : </p>
  
  <p><code>(xls[xls['DisabilityFriendly'] == 'приспособлен для всех групп инвалидов']) &amp; (xls[xls['Paid'] == 'бесплатно'])</code></p>
  
  <p>Can anyone explain why?</p>