video 34 add_url and app route principle
video 35,36 standard class view, see https://www.cnblogs.com/two-peanuts/p/11342492.html
video 38 blueprint
video 34 add_url and app route principle
video 35,36 standard class view, see https://www.cnblogs.com/two-peanuts/p/11342492.html
video 38 blueprint