title: Group dataframe and get sum AND count?
body: <p>I have a dataframe that looks like this:</p>
  
  <pre><code>              Company Name              Organisation Name  Amount
  10118  Vifor Pharma UK Ltd  Welsh Assoc for Gastro &amp; Endo 2700.00
  10119  Vifor Pharma UK Ltd    Welsh IBD Specialist Group,  169.00
  10120  Vifor Pharma UK Ltd             West Midlands AHSN 1200.00
  10121  Vifor Pharma UK Ltd           Whittington Hospital   63.00
  10122  Vifor Pharma UK Ltd                 Ysbyty Gwynedd   75.93
  </code></pre>
  
  <p>How do I sum the <code>Amount</code> and count the <code>Organisation Name</code>, to get a new dataframe that looks like this?</p>
  
  <pre><code>              Company Name             Organisation Count   Amount
  10118  Vifor Pharma UK Ltd                              5 11000.00
  </code></pre>
  
  <p>I know how to sum <em>or</em> count:</p>
  
  <pre><code>df.groupby('Company Name').sum()
  df.groupby('Company Name').count()
  </code></pre>
  
  <p>But not how to do both!</p>