持续收到错误-builtins.AttributeError：“ int”对象没有属性“ isdigit”

Question

First part is working fine but Whenever i enter name of the file in grades = input() i receive AttributeError.

print('Choose one of the following options:')
print('1. Calculate the average grade for each student.')
print('2. Print the highest or lowest scores based on the user input.')
print('3. Find the average score of the entire class (all students) in the 
final exam.')
print('4. To quit')

option = input('Enter your option: ')
while True:



    if not option.isdigit() or not int(option)>0 :
        print('Please enter a valid option from 1 to 4')
        option = input('Enter your option: ')
        continue

    option = int(option)
    if option in [1,2,3,4] :
        grades = input('Enter the name of the file')

    else: 
        print('Please enter a valid option from 1 to 4')
        option = input('Enter your option: ')

Answer 1

You can really simplify this code:

print('Choose one of the following options:')
print('1. Calculate the average grade for each student.')
print('2. Print the highest or lowest scores based on the user input.')
print('3. Find the average score of the entire class (all students) in the final exam.')
print('4. To quit')

option = input('Enter your option: ')

while True:
    if option in ['1', '2', '3', '4']:
        option = int(option)
        grades = input('Enter the name of the file')
    else: 
        print('Please enter a valid option from 1 to 4')
        option = input('Enter your option: ')

Answer 2

为什么不使用简单的强制转换来确保输出的类型始终是str？

option = str(input('Enter your option: '))