title: search dataframe for a keyword in any column and get the rows
body: <p>I have  a dataframe which I wish to get a subset by checking for the presence of  a keyword across all columns in all rows one by one.
  Here is the snippet:</p>
  
  <pre><code>df.apply(lambda x: x.str.contains('TEST')).any()
  </code></pre>
  
  <p>but because not all column values are of string type  and so it throws error:</p>
  
  <blockquote>
    <p>AttributeError: ('Can only use .str accessor with string values</p>
  </blockquote>
  
  <p>Any help is  appreciated.</p>