如何在 str() 中禁用计算

Question

def LastDigit(num):
    last_digit = str(num)[-1]
    return last_digit 

If I input 1235-4578-9899-2231 (without quotation mark), the function will return the last digit. The trouble is that if I input without quotation mark, Python will do automatic subtraction, instead of treating my input as a string in a whole.

Answer 1

This is not possible. 1235-4578-9899-2231 is code featuring subtraction operators. The interpreter cannot know that you mean it to be a string without quote marks.

Answer 2

You can fix it by converting your function argument which is num into string before calling the function.

def LastDigit(num):
  last_digit = str(num)[-1]
  return print(last_digit)

LastDigit("1235-4578-9899-2231")