title: Pandas how to use pd.cut()
body: <p>Here is the snippet:</p>
  
  <pre><code>test = pd.DataFrame({'days': [0,31,45]})
  test['range'] = pd.cut(test.days, [0,30,60])
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>    days    range
  0   0       NaN
  1   31      (30, 60]
  2   45      (30, 60]
  </code></pre>
  
  <p>I am surprised that 0 is not in (0, 30], what should I do to categorize 0 as (0, 30]?</p>