title: Convert list to dictionary with duplicate keys using dict comprehension
body: <p>Good day all,</p>
  
  <p>I am trying to convert a list of length-2 items to a dictionary using the below:</p>
  
  <pre><code>my_list = ["b4", "c3", "c5"]
  my_dict = {key: value for (key, value) in my_list}
  </code></pre>
  
  <p>The issue is that when a key occurrence is more than one in the list, only the last key and its value are kept.</p>
  
  <p>So in this case instead of </p>
  
  <pre><code>my_dict = {'c': '3', 'c': '5', 'b': '4'}
  </code></pre>
  
  <p>I get </p>
  
  <pre><code>my_dict = {'c': '5', 'b': '4'}
  </code></pre>
  
  <p>How can I keep all key:value pairs even if there are duplicate keys.
  Thanks</p>