#python calculator
print ('calculator, enter what you want:','A = multiple,','B = division,', 'C = add,', 'D = substract')
answer = input ()
answer = str [A, B, C, D]
if answer == A or a:
print ('enter your first number')
first_number_ = int(input())
print ('enter your second number')
second_number_ = int(input())
result1 = first_number_ * second_number_
print ('result=', answer2)
请问下为什么A是not defined啊,还有改成if input() == A or a:了之后后面为什么不会运行了啊?
#请无视语法错误