title: Python-pandas, np.nan
body: <p>Could you guys please help me explain the code below:</p>
  <p>Why a <code>nan</code> is not <code>np.nan</code>?</p>
  <pre><code>import pandas as pd
  import numpy as np
  
  df.iloc[31464]['SalesPersonID']
  [out]:
  nan
  
  df.iloc[31464]['SalesPersonID'] is np.nan
  [out]:
  False
  </code></pre>
  <p>Thank you, all.</p>