title: python floating number
body: <p>i am kind of confused why python add some additional decimal number in this case, please help to explain</p>
  
  <pre><code>&gt;&gt;&gt; mylist = ["list item 1", 2, 3.14]
  &gt;&gt;&gt; print mylist ['list item 1', 2, 3.1400000000000001]
  </code></pre>