[Django]-How to implement the SimpleMiddleware?

Since you are writing a new-style middleware, you should use MIDDLEWARE instead of MIDDLEWARE_CLASSES in your settings.

You also need to make sure that your entry in the settings matches the location of the middleware. The entry 'portal.middleware.SimpleMiddleware' suggests a SimpleMiddleware class in portal/middleware.py, which does not match your filename portal/middleware/MiddleWare.py.