title: python dictionary key pointing to value of another key in the same dictionary
body: <p>I have a python dictionary that has the below format</p>
  
  <pre><code>data = {  'key1': 'value1',
    'key2': 'value2',
    'key3': 'value3'
  }
  </code></pre>
  
  <p>I want this <code>key3</code> value to point to the value of <code>key1</code>.
  what i tried so far is 
  <code>'key3': key1['value1']</code> or <code>'key3': data['key1']</code> and both of them seem to be invalid syntaxes.</p>