BCrypt hash a String in Haskell

import Crypto.KDF.BCrypt (hashPassword)
import qualified Data.ByteString.Char8 as B
import Data.ByteString.Base64 (encode,decode)
import System.Environment

runArgs :: [String] -> IO B.ByteString
runArgs [a] = do
  hash a

hash :: String -> IO B.ByteString
hash a = hashPassword 6 (B.pack a) :: IO B.ByteString


main :: IO ()
main = do
  args <- getArgs
  b <- runArgs args
  putStrLn (show b)

#!/usr/bin/env python3

import bcrypt
import sys

passwd = sys.argv[1].encode("utf-8")
hashed = sys.argv[2].encode("utf-8")

if bcrypt.checkpw(passwd, hashed):
    print("match")
else:
    print("does not match")