Ordinalize an integer

ordinalize.py

#!/opt/homebrew/bin/python3

import sys

def ordinalize(n):
  if n % 100 in (11, 12, 13):
    return f"{n}th"
  else:
    match n % 10:
      case 1:
        return f"{n}st"
      case 2:
        return f"{n}nd"
      case 3:
        return f"{n}rd"
      case _:
        return f"{n}th"

try:
  num = int(sys.argv[1])
except IndexError:
  print("You must supply an integer as a commandline argument")
  exit(1)
except ValueError:
  print("You must supply a valid integer")
  exit(1)

print(ordinalize(num))