title: Getting the size of a groupby operation in Pandas
body: <p>I've been performing a groupby operation on a dataframe I have that aggregates columns together based on the column 'Name':</p>
  
  <pre><code>Name | As | Bs | Cs   |  Note
  Mark   3     4     7     Good
  Luke   2     1     12    Well
  Mark   5     6     8     Ok
  John   1     18    3     Great
  </code></pre>
  
  <p>So in this case, the rows with 'Mark' are aggregated together on columns A,B, and C using this code:</p>
  
  <pre><code>temp_df = temp_df.groupby(['Name'], as_index=False).agg({'As': np.sum, 'Bs': np.sum,'Cs': np.sum})
  </code></pre>
  
  <p>A thing I need to add in is to do a count on the number of rows that have the same value in 'Name'. This would give me an output like:</p>
  
  <pre><code>Name | As | Bs | Cs   |  Note   | Count
  Mark   8     10    15    Good      2
  Luke   2     1     12    Well      1
  John   1     18    3     Great     1
  </code></pre>
  
  <p>How do I modify the above line of code to do what I need?       </p>