Python Postgres pull as byte object vs str

I'm doing a basic Python Flask application with a Postgres database using psycopg2. I'm having trouble setting up the user registration password hash as it appears I'm working with a string vs byte type. Fundalmentally, I'll get this error when doing the password re-hash on the login (after registration and initial hash)

hash_value = hashlib.pbkdf2_hmac( # TypeError: a bytes-like object is required, not 'str' 

Here is the relevant table setup:

CREATE TABLE IF NOT EXISTS myschema.mytable ( --Unrelated fields... password_hash character varying(500) COLLATE pg_catalog."default" NOT NULL, salt character varying(100) COLLATE pg_catalog."default" NOT NULL, --More unrelated fields... ) 

This is how I'm inserting the data:

# Code above that is setting up a DB utility, configs, etc... # Hash the password salt = os.urandom(16) iterations = 100000 hash_value = hashlib.pbkdf2_hmac( 'sha256', password.encode('utf-8') + app_config['PEPPER'].encode('utf-8'), salt, iterations ) password_hash = salt + hash_value # Redacted extra fields query = "INSERT INTO mytable (password_hash, salt) VALUES (%s, %s);" params = (password_hash, salt) # This kicks off the standard cursor execute, etc... db.query(query, params) 

And for the retrieval:

# Code above that is setting up a DB utility, configs, etc... query = "SELECT password_hash, salt FROM mytable WHERE email = %s;" params = (email,) users = db.query(query, params) db.close() # No user found if not users: return False db_password_hash, db_salt = users[0] iterations = 100000 hash_value = hashlib.pbkdf2_hmac( # This will be the spot that throws the exception as it expects bytes for 'sha256', password.encode('utf-8') + app_config['PEPPER'].encode('utf-8'), db_salt, iterations ) # Then commence validation logic, etc... 

I have tried using bytes(db_salt, 'utf-8') as it's really throwing the error on the salt field. However, this will not yield a successful rehash. I'll take recommendations - this is new development so if I need to do a postgres binary type I can do that too- whatever option makes sense here.

Thanks!