title: Is there any difference between using Dataframe.columns and Dataframe.keys() to obtain the column names?
body: <p>For the sake of curiosity is there any practical difference between getting the column names of a DataFrame (let's say df) by using df.columns or df.keys()? </p>
  
  <p>I've checked the outs by type and it seems to be exactly the same. Am I missing something or these two methods are just as redundant as it seems? Is one more appropriate to use than the other?</p>
  
  <p>Thanks.</p>