title: How do I sort a dictionary by key?
body: <p>How do I sort a dictionary by its keys?</p>
  <p>Example input:</p>
  <pre><code>{2:3, 1:89, 4:5, 3:0}
  </code></pre>
  <p>Desired output:</p>
  <pre><code>{1:89, 2:3, 3:0, 4:5}
  </code></pre>