Program:

GradeBook.py

Scenario:

A high school teacher needs to track students' grades and calculate averages for

reports. You are tasked to develop this system.

Task:

Write a Python class named GradeBook with the following components:

Fields:

grades $($list of floats$)$: A list to hold grades

Constructors:

A constructor that initializes the grades with an empty list.

Methods:

add$\_$grade$($grade $)$: Adds a grade to the list. If the grade is not between $0$

and $100,$ raise a ValueError with the message "Invalid grade"

calculate$\_$average$()$: Calculates and returns the average of the grades in

the list.

$\_$ str$\_()$: Returns a string that shows all grades and the average.

In the main method, create instances of GradeBook, add grades, calculate the average,

and handle any exceptions that arise.