title: 'numpy.ndarray' object has no attribute 'count'
body: <p>I have the following DataFrame:</p>
  
  <pre><code>df  = pd.DataFrame({'Label': list('AABCCC'), 'Values':  [1,2,3,4,np.nan,8] })
  </code></pre>
  
  <p>I want to drop those groups that do not have a minimum number of items (one or less) so I tried the following:</p>
  
  <pre><code>f = lambda x: x.Values.count() &gt; 1
  
  df.groupby('Label').filter(f)
  </code></pre>
  
  <p>However, this raised an error:</p>
  
  <blockquote>
    <p>Error : 'numpy.ndarray' object has no attribute 'count'</p>
  </blockquote>
  
  <p>Where did it go wrong?</p>