Untitled

def get_grade(student_name, gradebook):
    try:
        grade = gradebook[student_name]
        return f"{student_name}'s grade is {grade}."
    except KeyError:
        return f"Error: {student_name} is not in the gradebook."

# Main program
def main():
    gradebook = {
        "Alice": "A",
        "Bob": "B",
        "Charlie": "C",
        "Diana": "A"
    }

    print("Welcome to the Grade Lookup System!")
    print("Students in the gradebook: Alice, Bob, Charlie, Diana\n")

    while True:
        student_name = input("Enter a student's name to look up their grade (or type 'exit' to quit): ")

        if student_name.lower() == "exit":
            print("Exiting the program. Goodbye!")
            break

        result = get_grade(student_name, gradebook)
        print(result)

# Run the main program
if __name__ == "__main__":
    main()