title: How to concatenate values of two variables in Pandas
body: <p>I have 2 variable data frame. I want to concatenates values of these to variables into a new variable using python.
  How can I do this?</p>
  
  <p>E.g.:</p>
  
  <p><img src="https://i.stack.imgur.com/YQEDw.png" alt="enter image description here"></p>