title: Eliminating duplicates in a data frame works, but when I save the CSV and reload it, more duplicates appear
body: <p>I have this big DataFrame with around 9 million rows. I want to eliminate all duplicate rows, and I do so by using drop_duplicates(), which is fine until I save the new file to disk and reload it.</p>
  <p><a href="https://i.stack.imgur.com/rlrgi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rlrgi.png" alt="Code used" /></a></p>
  <p>Can you help me understand what is going on here? Is there something that I'm missing?</p>