title: Python Pandas: get rows of a DataFrame where a column is not null
body: <p>I'm filtering my DataFrame dropping those rows in which the cell value of a specific column is None.</p>
  
  <pre><code>df = df[df['my_col'].isnull() == False]
  </code></pre>
  
  <p>Works fine, but PyCharm tells me:</p>
  
  <blockquote>
    <p>PEP8: comparison to False should be 'if cond is False:' or 'if not cond:'</p>
  </blockquote>
  
  <p>But I wonder how I should apply this to my use-case? Using 'not ...' or ' is False' did not work. My current solution is:</p>
  
  <pre><code>df = df[df['my_col'].notnull()]
  </code></pre>