Even if the first command in if is true it doesn't print what i want , it only print the else command

Question

numberchk=(int(input(\"Enter a Roman numeral or a Decimal numeral:\" )))
def int2roman(number):
    numerals={1:\"I\", 4:\"IV\", 5:\"V\", 9: \"IX\", 10:\"X\", 40:\"XL\",         


        

Answer 1

Use isinstance(numberchk, int) instead, because int is a type but numberchk is an instance of that type.

Since int(input(... always returns an integer as long as it can, you don't have to check it using if-else. To suppress error raising if input is not an integer, use try-except as @poke mentioned.

You can also use a while-loop and break to request the user input repeatedly until you get an legal input:

while True:
    try:
        numberchk=int(input("Enter a Roman numeral or a Decimal numeral:" ))
        break
    except ValueError:
        print('error')
print(int2roman(numberchk))