grade = A

if (grade == A):
    print("Excellent")
添加一个for循环，修改给定的代码
grades = ["A", "B", "C", "D"]

for grade in grades:
    if (grade == "A"):
        print("优秀")
    elif (grade == "B"):
        print("良好")
    elif (grade == "C"):
        print("平均")
    elif (grade == "D"):
        print("差")