def generate_id(self, session_key):

    """Method for generating unique session ids"""
    generated_id = os.urandom(10).hex()
    while generated_id in session[session_key]:
        generated_id = os.urandom(10).hex()
    return generated_id

def __init__(self, username, email, password):
    self.username = username
    self.email = email
    self.password = password
    self.userid = self.generate_id('users')

def __init__(self, categoryname):
    self.categoryname = categoryname
    self.category_id = self.generate_id('recipe_category')
    self.userid = session['logged_in']['userid']

def __init__(self, name, category_id):
    self.name = name
    self.category_id = category_id
    recipe_category.category_id = category_id
    self.recipe_id = self.generate_id('recipes')
    self.userid = session['logged_in']['userid']