title: convert text columns into numbers in sklearn
body: <p>I'm new to data analytics. I'm trying some models in python Sklearn. I have a dataset in which some of the columns have text columns. Like below,</p>
  
  <p><strong>Dataset</strong>  </p>
  
  <p><img src="https://i.stack.imgur.com/BRWf6.png" alt=""></p>
  
  <p>Is there a way to convert these column values into numbers in pandas or Sklearn?. Assigning numbers to these values will be right?. And what if a new string pops out in test data?.</p>
  
  <p>Please advice.</p>