title: Rename files based on filenames in a csv
body: <p>I have a csv file 'names.csv' containing two columns 'old_name' and 'new_name' such that each row has new names corresponding to the old file names.
  I want to replace all the old filenames of the files in '/home/docs/abc' directory with the new names. (The names file is in the same directory and no need to change its name). I am tyring with the csv module and array method but unable to get the results.File extension will remain same '.csv'</p>