title: How to tell if series elements contain question mark in Python?
body: <p>I have a series of text posts (df['posttext']). Each of the rows in this series are strings. I want to know which ones contain a question mark.</p>
  
  <p>When I try</p>
  
  <pre><code>df['posttext'].str.contains("?")
  </code></pre>
  
  <p>I get this:</p>
  
  <pre><code>error: nothing to repeat at position 0.
  </code></pre>