Thanks @eyeveebe for replying. My problem statement was
I am writing a token value to the csv file at every 30 min and i was trying to read the value after from the csv file .
So i was trying to read the data dynamically from the csv file …so that when the new token was written to the file , i can read it after 30 min or so and pass that value to the other api 
. I have posted the problem statement in another topic on community [ Calling Token API every hour - #2 by hbadger ]
However when i was trying this , i couldn’t anything which can help in reading data dynamically from the csv file .