title: Python transform list of dictionaries into another list of dictionaries
body: <p>I have a list of dictionaries in python. Here is a contrieved example with hair color and race.</p>
  
  <pre><code>some_list = [
          {'blond': 3, 'race': 'WHITE'},
          {'black': 4, 'race': 'WHITE'},
          {'light brown': 6, 'race': 'WHITE'},
          {'black': 2, 'race': 'AFRICAN_AMERICAN'},
          {'blond': 1, 'race': 'AFRICAN_AMERICAN'},
          {'dark brown': 1, 'race': 'AFRICAN_AMERICAN'}
  ]
  </code></pre>
  
  <p>The hair color is one of the keys and the value for the hair color is the count of how many people have that hair color for the given race. I do not know how many hair colors there are nor do I know how many races there are. I want to transform this list to include counts of ALL hair colors for ALL races such that the result would include 0 counts for colors not listed for a given race:</p>
  
  <pre><code>some_list = [
          {'blond': 3, 'race': 'WHITE'},
          {'black': 4, 'race': 'WHITE'},
          {'light brown': 6, 'race': 'WHITE'},
          {'dark brown': 0, 'race': 'WHITE'},
          {'black': 2, 'race': 'AFRICAN_AMERICAN'},
          {'blond': 1, 'race': 'AFRICAN_AMERICAN'},
          {'dark brown': 1, 'race': 'AFRICAN_AMERICAN'},
          {'light brown': 0, 'race': 'AFRICAN_AMERICAN'}
  ]
  </code></pre>
  
  <p>For the life of me I can't think of a simple 'python' way to do this easily. Surely there is a trick to this? Anyone know a succient way to solve this?</p>