Python 3中的循环和条件语句问题

我是一个非常开始的程序员，我正在尝试为大学的教授创建一个年级书计划，以便他可以输入他的期中和期末考试成绩，并为每门课程的每个学生获得平均和字母成绩。该程序应该获得课程编号，课程级别，考试数量和学生信息（ID和考试分数）的输入。

最初，我想创建一个以ID为键，平均值为值的字典，但是那似乎不起作用，所以我开始尝试创建带条件的while循环。

基本上，代码是一团糟，我不确定自己做错了什么。我已经看过教程并在线阅读了很多东西，但是我为此感到困惑。一方面，我在第22行的elif语句中不断收到无效语法错误。任何人都可以给予的任何帮助，我们将不胜感激！对于我在这里遗漏的任何内容，我们会提前道歉-我是新来的。

谢谢！

print("Hello! Welcome to your Grading Program!\n")
courseCode = input("Please enter the course code : ")
courseLevel = input("Please enter the course level : ")
numberExams = float(input("Please enter the number of exams : "))
enterStudents = input("Would you like to input a student, Yes or No? : ")

student = 0

while enterStudents == "Yes" or "yes" or "y" or "Y" :
    if courseLevel == "undergrad" or "Undergrad" or "undergraduate" or "u" or "U":
        for student in range(int(numberExams)):
            ID = input("Please enter student ID: ")
            midterm = int(float(input("Please enter midterm score: ")))
            finalExam = int(float(input("Please enter final exam score: ")))
            undAverage = (midterm * .60) + (finalExam * .40)
    elif courseLevel == "grad" or "Grad" or "Graduate" or "g" or "G":
        for student in range(int(numberExams)):
            ID = input("Please enter student ID: ")
            midterm = int(float(input("Please enter midterm score: ")))
            finalExam = int(float(input("Please enter final exam score: ")))
            undAverage = (midterm * .30) + (finalExam * .70)               
elif enterStudents == "No" or "no" or "n" or "N" :
    print("\nSee you next time!")
else:
    enterStudents == "" :
        input("Invalid Entry! Would you like to input a student, Yes or No?:")

def Grade():
    for letter in Grade:
        total = 100
    for letter in Grade(A,B,C,D,E,F):
        if undGrade == "A":
                    undAverage >= range(85,101)
        elif undGrade == "B":
                    undAverage >= range(70,85)
        elif undGrade == "C":
                    undAverage >= range(55,70)
        elif undGrade == "D":
                    undAverage >= range(40,55)
        elif undGrade == "F":
                    undAverage >= range(0,40)
    print(Grade)