5.7. Exercise: Database Migration

You are working for a fan club website, and for pricing reasons, management told you that they have decided to change the database service. Since you are in charge of the database, you are also in charge of the database migration. You need to read from your old database files and create new files that are compatible with the new database service.

The old database files are in the following format:

Actor,EpisodeCount,LastOccurence
Kenan Thompson,353,2020
Seth Meyers,255,2018
Fred Armisen,238,2020
Kate McKinnon,179,2020

New database files should be in the following format:

Actor:Kenan Thompson,EpisodeCount:353,LastOccurence:2020
Actor:Seth Meyers,EpisodeCount:255,LastOccurence:2018
Actor:Fred Armisen,EpisodeCount:238,LastOccurence:2020
Actor:Kate McKinnon,EpisodeCount:179,LastOccurence:2020

Write a function named format_for_migration which takes input two string values as file paths for input and output files, where the format of the input and the output files are shown above. This function must fill the output file with the records. The function should also return an integer which is the number of records that are formatted.

Hint: You can use the built-in map(), join(), rstrip() and split() functions.

Sample I/O:

Sample function call:
    format_for_migration("input.txt", "output.txt")

Content of the file "input.txt":
    Actor,EpisodeCount,LastOccurence
    Kenan Thompson,353,2020
    Seth Meyers,255,2018
    Fred Armisen,238,2020
    Kate McKinnon,179,2020
    Cecily Strong,174,2020
    Bill Hader,167,2020
    Maya Rudolp,166,2020
    Will Forte,159,2016
    Tina Fey,154,2020
    Tracy Morgan,154,2019
    Amy Poehler,153,2020
    Will Ferrell,151,2019
    Rachel Dracht,150,2020
    Colin Jost,149,2020
    Kristen Wiig,145,2020
    Andy Samberg,144,2018
    Michael Che,132,2020
    Pete Davidson,132,2020
    Alec Baldwin,65,2020
    Julia Louis-Dreyfus,60,2016
    Jenny Slate,22,2010
    Steve Martin,32,2019
    Martin Short,28,2020
    Nancy Carell,22,2018
    Steve Carell,18,2018
    Tom Hanks,18,2020
    John Mulaney,14,2020

Return value:
    27

Content of the file "output.txt" after function call:
    Actor:Kenan Thompson,EpisodeCount:353,LastOccurence:2020
    Actor:Seth Meyers,EpisodeCount:255,LastOccurence:2018
    Actor:Fred Armisen,EpisodeCount:238,LastOccurence:2020
    Actor:Kate McKinnon,EpisodeCount:179,LastOccurence:2020
    Actor:Cecily Strong,EpisodeCount:174,LastOccurence:2020
    Actor:Bill Hader,EpisodeCount:167,LastOccurence:2020
    Actor:Maya Rudolp,EpisodeCount:166,LastOccurence:2020
    Actor:Will Forte,EpisodeCount:159,LastOccurence:2016
    Actor:Tina Fey,EpisodeCount:154,LastOccurence:2020
    Actor:Tracy Morgan,EpisodeCount:154,LastOccurence:2019
    Actor:Amy Poehler,EpisodeCount:153,LastOccurence:2020
    Actor:Will Ferrell,EpisodeCount:151,LastOccurence:2019
    Actor:Rachel Dracht,EpisodeCount:150,LastOccurence:2020
    Actor:Colin Jost,EpisodeCount:149,LastOccurence:2020
    Actor:Kristen Wiig,EpisodeCount:145,LastOccurence:2020
    Actor:Andy Samberg,EpisodeCount:144,LastOccurence:2018
    Actor:Michael Che,EpisodeCount:132,LastOccurence:2020
    Actor:Pete Davidson,EpisodeCount:132,LastOccurence:2020
    Actor:Alec Baldwin,EpisodeCount:65,LastOccurence:2020
    Actor:Julia Louis-Dreyfus,EpisodeCount:60,LastOccurence:2016
    Actor:Jenny Slate,EpisodeCount:22,LastOccurence:2010
    Actor:Steve Martin,EpisodeCount:32,LastOccurence:2019
    Actor:Martin Short,EpisodeCount:28,LastOccurence:2020
    Actor:Nancy Carell,EpisodeCount:22,LastOccurence:2018
    Actor:Steve Carell,EpisodeCount:18,LastOccurence:2018
    Actor:Tom Hanks,EpisodeCount:18,LastOccurence:2020
    Actor:John Mulaney,EpisodeCount:14,LastOccurence:2020