problem creating users via pythons script

this is really newb of me but i can't manage to make a script to create
users.

cur.execute("""CREATE USER %s WITH PASSWORD %s IN GROUP %s
""",(StaffUserName,NewPassword,StaffGroup))

produces this error

ERROR:  syntax error at or near "'bob.smith'" at character 13

is it because i need to double quote or something? i'm sure the answer
is stupid and i'm just too tired.