title: how to check if a value exists in a dataframe
body: <p>hi I am trying to get the column name of a dataframe which contains a specific word,</p>
  
  <p>eg:
  i have a dataframe,</p>
  
  <pre><code>NA              good    employee
  Not available   best    employer
  not required    well    manager
  not eligible    super   reportee
  
  my_word=["well"]
  </code></pre>
  
  <p>how to check if "well" exists in a df and the column name which has "well"</p>
  
  <p>thanks in Advance!</p>