An Introduction to Programming, Using Python. By David Schneider

Chapter 5 Section 5.2

24. Create a python program to read off of a file named Cowboy.txt and reduce the prices of each item by 20%, creating a new text file (outfile) named Cowboys2.txt with the updated prices replacing the old.

Cowboy.txt contents:

Colt Peacemaker,12.20 Holster,2.00 Levi Strauss jeans,1.35 Saddle,40.00 Stetson,10.00