import hashlib

def calc_md5(password):
    md5 = hashlib.md5()
    md5.update(password.encode('utf-8'))
    return md5.hexdigest()

def login(user, password):
    return db.get(user) == calc_md5(password)

def login(username, password):
    user = db[username]
    return user.password == get_md5(password + user.salt )