(파이썬) 뭐가 문제인지 봐주세요 ㄹㅇ 간절함

게시물 수정 , 삭제는 로그인 필요

(인풋)

selection = input('Select an operation to perform.\n******************\n(A)dd filters, (P)rint names, (G)raph data, Remove (F)ilter, (E)xit: ')

selection = selection.upper()

while selection != 'E':

    if selection == 'A' or selection == 'a':

        print('(G)enre, Release (Y)ear, (R)ating: ')

        choiceA = input()

 if choiceA == 'R' or choiceA == 'r':

            print('Choose the rating.: ', Rating)

            rating1 = input('From: ')

            rating1 = rating1.upper()

            for itemR in Rating:

                if rating1 != itemR:

                    print('Error!!! Enter again.')

                    rating1 = input('From: ')

            rating2 = input('To: ')

            rating2 = rating2.upper()

            for itemR in Rating:

                if rating2 != itemR:

                    print('Error!!! Enter again.')

                    rating2 = input('To: ')

            print(rating1, rating2)

(아웃풋)

Choose the rating.:  ['NR', 'G', 'PG', 'PG-13', 'M', 'MA', 'R']

From: R

Error!!! Enter again.

From: NR

Error!!! Enter again.

From: G

Error!!! Enter again.

From: PG

Error!!! Enter again.

From: ma

Error!!! Enter again.

From: g

Error!!! Enter again.

From: pg-13

Error!!! Enter again.

From: PG-13

To: R

Error!!! Enter again.

To: MA

Error!!! Enter again.

To: ma

Error!!! Enter again.

To: m

Error!!! Enter again.

To: MA

Error!!! Enter again.

To: r 

Error!!! Enter again.

To: R

PG-13 R

왜 에러가 랜덤으로 뜨죠?