Question

INTRO

I’ve recently switched to Python, after about 10 years of PHP development and habits.

Eg. in Symfony2, every request to server (Apache for instance) has to load eg. container class and instantiate it, to construct the “rest” of the objects.

As far as I understand (I hope) Python’s WSGI env, an app is created once, and until that app closes, every request just calls methods/functions.

This means that I can have eg. one instance of some class, that can be accessed every time, request is dispatched, without having to instantiate it in every request. Am I right?

QUESTION

I want to have one instance of class since the call to __init__ is very expensive (in both computing and resources lockup). In PHP instantiating this in every request degrades performance, am I right that with Python’s WSGI I can instantiate this once, on app startup, and use through requests? If so, how do I achieve this?

Answer 1

The best method I found was mentioned (and I missed it earlier) in Pyramid docs:

From Pyramid Docs#Startup

Note that an augmented version of the values passed as **settings to the Configurator constructor will be available in Pyramid view callable code as request.registry.settings. You can create objects you wish to access later from view code, and put them into the dictionary you pass to the configurator as settings. They will then be present in the request.registry.settings dictionary at application runtime.