why does me delimiter / replace not remove commas in my csv file?

And also how do i change the date format from YYYY-MMM to DD-MM-YYYY(for example: 2022 Jan-> 01-01-2022(all the days start with day 01 since there is no day) only with using import datetime and import csv, no pandas). I tries using ai and just googling it ,but it does'nt work(or its using pandas), gives me constant errors for some reason. Please help, would greatly appreciate it