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\",
Try using isdigit() function.
replace this part on your code
if numberchk==int:
with
if numberchk.isdigit():