title: Why `0.4/2` equals to `0.2` meanwhile `0.6/3` equals to `0.19999999999999998` in python?
body: <p>I know these are float point division. But why did these two formula behave differently?</p>
  
  <p>And I did some more investigation, the result confusing me even more:</p>
  
  <pre><code>&gt;&gt;&gt;0.9/3
  0.3
  
  &gt;&gt;&gt;1.2/3
  0.39999999999999997
  
  &gt;&gt;&gt;1.5/3
  0.5
  </code></pre>
  
  <p>What's the logic here to decide whether the result is printed with one decimal place or more?</p>
  
  <p>PS: I used python3.4 to do the experiment above.</p>