I need help on this part... which is function portfolio_value, please explain the approach of the answer.

python Almost there. Now that you have unctions to read the vanaus prelab as you will need to call those functions to complete this part. iles and add all the data into data stri tures you are ready compute the final va ue of the no olio Paste ur rode rom the prev ous two parts o this Reminder of the data formats: The input file wil be a CSV file with each row in the format buyor sellquantity,ticker.date" where buy or_sell is either the string "buy or "sell, quantity is an integer representing the number of shares traded, ticker is a string representing the ticker symbol heing traded, and date is the date of the trade in the format YYYY-MM-DD. You may assume there are files named