title: How to check if all substring in pandas column are the same?
body: <p>I have this <a href="https://i.stack.imgur.com/wcbA7.png" rel="nofollow noreferrer">column</a>
   and I want to check if all strings have <code>anr12</code> substring. How to check this? And if all substrings are the same, how to drop this particular substring?</p>