title: How to check if a particular cell in pandas DataFrame isnull?
body: <p>I have the following <code>df</code> in pandas.</p>
  
  <pre><code>0       A     B     C
  1       2   NaN     8
  </code></pre>
  
  <p>How can I check if <code>df.iloc[1]['B']</code> is NaN?</p>
  
  <p>I tried using <code>df.isnan()</code> and I get a table like this:</p>
  
  <pre><code>0       A     B      C
  1   false  true  false
  </code></pre>
  
  <p>but I am not sure how to index the table and if this is an efficient way of performing the job at all?</p>