Lab 4.3 PYthon ONLY

1) Store a string such as Hello, Pyhong! in a string object. Change all

b) Lower-case letters to uppercase, and upper-case letter to lower-case.

c) Print the result one letter per line. Do this on the interactive shell.

Lab 4.4 Write a script that prints all text file names stored in your current

working directory.

Lab 4.5 Write a script that prints the grades and finds the average grade of the

grades stored in grades.txt (posted on e-learn).