title: Updating or adding keys to dicts
body: <p>I have many dicts, I'm giving 2 for this example:</p>
  
  <pre><code>dict1={'green': 3, 'yellow': 5, 'blue': 1}
  dict2={'green': 5, 'yellow': 1, 'blue': 3, 'purple': 10}
  </code></pre>
  
  <p>I've been trying to find a way to add the 2 dicts so i can have updated values(sum) for existing keys, and added up keys and values for non-existant ones.</p>
  
  <p>Results:</p>
  
  <pre><code>results = {'green': 8, 'yellow': 6, 'blue': 4, 'purple': 10}
  </code></pre>
  
  <p>I tried <code>dict1.update(dict2)</code> but as you know , I've only got a dictionary with updated values, not summed up.</p>
  
  <p>Any ways to achieve this?</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>Solved : Actually collections.Counter did the trick ... Thanks</p>