title: Remove row from dataframe if column value
body: <p>If I have a dataframe like this:</p>
  
  <pre><code>index   col1   col2 
  a        a1     a2
  b        b1     b2
  c        c1     b2
  </code></pre>
  
  <p>Is it possible to use the <code>.drop()</code> to delete rows which have a sudden value in one of their columns?</p>
  
  <p>Something like: <code>df.drop(col2 = 'b2')</code></p>