title: How to count occurrence of elements in a single column of Pandas Dataframe
body: <p>I have the following DF:</p>
  
  <pre><code>import pandas as pd
  data = pd.DataFrame({'name' : ['a', 'a', 'b', 'd']})
  In [7]: data
  Out[7]:
    name
  0    a
  1    a
  2    b
  3    d
  </code></pre>
  
  <p>What I want to do is to summarize</p>
  
  <pre><code>a 2
  b 1
  d 1
  </code></pre>
  
  <p>How can I do it?
  Tried this but not good:</p>
  
  <pre><code>g = data.groupby('name')
  g.count()
  </code></pre>