title: What are the reasons to use the id function in Python?
body: <p>In Python, we can use the <code>id</code> function. Why are the following outputs different? </p>
  
  <pre><code>&gt;&gt;&gt; id(123)
  1824812112
  &gt;&gt;&gt; id(1)
  1824810160
  &gt;&gt;&gt; id(5)
  1824810224
  &gt;&gt;&gt; id(666)
  123868896
  </code></pre>