title: How to determine if there are non-string values in a Pandas Series
body: <p>I am trying to use boolean indexing on a Pandas Series in order to determine if there are values in my Series that are not strings.  </p>
  
  <p>My approach so far is: </p>
  
  <pre><code>contains_non_string = s[type(s) != str].any()
  </code></pre>
  
  <p>When I run this, I get the following error: </p>
  
  <pre><code>TypeError: 'int' object is not subscriptable
  </code></pre>
  
  <p>How can I correctly determine if there are non-string values in my Series? I am running Python 3.6 and Pandas 0.19.2.</p>