title: Pandas deleting row with df.drop doesn't work
body: <p>I have a DataFrame like this (first column is <code>index</code> (786...) and second <code>day</code> (25...) and <code>Rainfall amount</code> is empty):    </p>
  
  <pre><code>Day Rainfall amount (millimetres)  
  786   25                              
  787   26                              
  788   27                              
  789   28                              
  790   29                              
  791    1                              
  792    2                              
  793    3                              
  794    4                              
  795    5 
  </code></pre>
  
  <p>and I want to delete the row 790. I tried so many things with df.drop but nothin happend.</p>
  
  <p>I hope you can help me.</p>