gistfile1.txt

def validation(user_input):

    colons = user_input.count(":")
    semicolons = user_input.count(";")

    if user_input[-1:] == ":":
        print("Invalid input, please try again!")
        return False

    if colons != (semicolons + 1):
        print("Invalid input, please try again!")
        return False

    else:
        return True


def previous_courses_func(previous_courses):
    student_previous = dict()
    previous_courses = previous_courses.split(";")

    for item in previous_courses:
        course, grade = item.split(":")
        student_previous[course] = grade.upper()

    return student_previous


def current_courses_func(current_courses):
    student_current = dict()
    current_courses = current_courses.split(";")

    for item in current_courses:
        course, grade = item.split(":")
        student_current[course] = grade.upper()

    return student_current


def show_grades(student_current, student_previous):

    for course, grade in student_current.items():
        if grade != "F":
            print(f"You can choose between S and {grade} for {course}.")
            student_current[course] = "S"

        elif course not in student_previous.keys():
            print(f"Your grade for {course} is U.")
            student_current[course] = "U"

        elif course in student_previous.keys():
            if student_previous[course] == "U":
                print(f"Your grade for {course} is U.")
                student_current[course] = "U"
            else:
                print(f"Your grade for {course} is F.")
                student_current[course] = "F"


def main():
    status = True

    while status:
        # Previous
        previous_courses = input(
            "Please enter the courses you have taken previously with letter grades:")
        status = validation(previous_courses)
        student_previous = previous_courses_func(previous_courses)
        print("Previous Courses and Grades: ", student_previous)
        print("\n")

        # Current
        current_courses = input(
            "Please enter the courses you have taken this semester with letter grades:")
        status = validation(current_courses)
        student_current = current_courses_func(current_courses)
        print("Current Courses and Grades: ", student_current)
        print("\n")

        # wanted
        wanted_course = input("Please enter the course you want to check: ")
        if(wanted_course not in student_current.keys()):
            print(f"You didn't take {wanted_course} this semester\n")

        show_grades(student_current, student_previous)

        check_try = input("Try again? y | n \n")
        if check_try == "y":
            continue
        else:
            break


main()