title: why and how to solve the data lost when multi encode in python pandas
body: <p><a href="https://drive.google.com/drive/folders/1y99lGWz9r-g7Kp-HvtCKUOgSOZf2xwzO?usp=sharing" rel="nofollow noreferrer">Download the Data Here</a></p>
  <p>Hi, I have a data something like below, and would like to multi label the data.</p>
  <p>something to like this: <a href="https://i.stack.imgur.com/LK0Zr.png" rel="nofollow noreferrer">target</a></p>
  <p>But the problem here is data lost when multilabel it, something like below:</p>
  <p><a href="https://i.stack.imgur.com/4wxhh.png" rel="nofollow noreferrer">issue</a></p>
  <p>using the coding of:</p>
  <pre><code>from sklearn.preprocessing import MultiLabelBinarizer
  
  mlb = MultiLabelBinarizer(sparse_output=True)
  
  df_enc = df.drop('movieId', 1).join(df.movieId.str.join('|').str.get_dummies())
  </code></pre>
  <p>Someone can help me, feel free to download the dataset, thank you.</p>