title: how to find specific data in many columns?
body: <p>a DataFrame name is df_y
  I want to find some data('K','m') on many columns
  so i made this code</p>
  <pre><code>df_y[df_y[['column1', 'column2', 'column3']].str.contains('K|M')]
  </code></pre>
  <p>then I could see a error &quot;'DataFrame' object has no attribute 'str'&quot;</p>
  <p>i think the code has problem by containg many columns...</p>
  <p>IDK how to make that correctly..!</p>