library/library_website/controllers/hello.py

from odoo import http
from odoo.http import request

class Hello(http.Controller):
    @http.route('/helloworld2', auth="public")
    def helloworld2(self):
        return('<h1>Hello World!</h1>')

    @http.route('/helloworlda', auth="public")
    def helloworlda(self, **kwargs):
        return request.render('library_website.helloworlda')

    @http.route('/hellocms/<page>', auth='public', website=True)
    def hello(self, page, **kwargs):
        return http.request.render(page)
    
    @http.route('/helloworld', auth="public", website=True)
    def helloworld(self, **kwargs):
        return request.render('library_website.helloworld')