title: pos_label=1 is not a valid label
body: <p>A newly created column 'Y' has 'No' or 'Yes' values as outputs for a binary classification.
  Getting the following error while trying to run a KNN classifier on the dataset. </p>
  
  <blockquote>
    <p>ValueError: pos_label=1 is not a valid label: array(['No', 'Yes'], dtype='
  </blockquote>
  
  <p>Anybody has any ideas?</p>
  
  <p>Thank you. </p>