title: In pandas, how to concatenate horizontally and then remove the redundant columns
body: <p>Say I have two dataframes.</p>
  
  <p>DF1:
  col1, col2, col3,</p>
  
  <p>DF2: col2, col4, col5</p>
  
  <p>How do I concatenate the two dataframes horizontally and have the col1, col2, col3, col4, and col5? Right now, I am doing pd.concat([DF1, DF2], axis = 1) but it ends up having two col2's. Assuming all the values inside the two col2 are the same, I want to have only one columns.</p>