python - create password hash / test password against hash

hash_password.py

import uuid
import hashlib

def hash_password(password, version=1, salt=None):
    if version == 1:
        if salt == None:
            salt = uuid.uuid4().hex[:16]
        hashed = salt + hashlib.sha1( salt + password).hexdigest()
        # generated hash is 56 chars long
        return hashed
    # incorrect version ?
    return None

def test_password(password, hashed, version=1):
    if version == 1:
        salt = hashed[:16]
        rehashed = hash_password(password, version, salt)
        return rehashed == hashed
    return False