[Answer]-Python: Command line arguments are incorrect

try to call your script as follows:

python myscript.py test 'pbkdf2_sha256$12000$EkKZXYXv0adl$GZppRyXed3a0y1uZMBR/F8Mu/rnpsN+7atY4hZAwlrQ='

the single quotes around the second argument will protect the string from being interpreted by the shell, as the shell understands anything that follows a $ as a shell variable.

As $EkKZXYXv0adl and $GZppRyXed3a0y1uZMBR obviously do not exist in your shell environment, they expand to nothing.