Grade calculator - decomposed

# Separate function to calculate the grade
def calculate_grade(student_score):
    if student_score >= 60:
        if student_score < 70:
            return "D"
        elif student_score < 80:
            return "C"
        elif student_score < 90:
            return "B"
        else:
            return "A"
    else:
        return "F"


# Separate function to get student information
def get_student_info():
    student_name = input("Enter student name (or type 'exit' to quit): ")

    if student_name.lower() == 'exit':
        return None, None

    student_score = int(input("Enter student score: "))
    return student_name, student_score


# Separate function to display the grade
def display_grade(student_name, student_score, student_grade):
    print(f"Student {student_name} scored {student_score} and received a grade of {student_grade}.")


# Main program
def main():
    print("Welcome to the Student Grade Calculator!")

    while True:
        student_name, student_score = get_student_info()

        if student_name is None:
            print("Goodbye!")
            break

        student_grade = calculate_grade(student_score)
        display_grade(student_name, student_score, student_grade)

if __name__ == "__main__":
    main()