title: add the prices according to the project id
body: <p>I have a dataframe called <code>resource_data</code>:</p>
  
  <pre><code>id      price
  p233245 149.00
  p069063 14.95
  p069063 8.45
  p069063 13.59
  p069063 24.95
  </code></pre>
  
  <p>and I want to remove duplicates in the id such that one single id contains the addition of the prices, for example, the above should become:</p>
  
  <pre><code>id  price
  p233245 149.00
  p069063 61.94
  </code></pre>