在Django中设置全局变量

Question

I am using elasticsearch and need to set up a persistent connection to it which I resuse anywhere in my project. However, after much digging I am still unsure how to properly create a global var which I can be sure will only be instantiated once. I have created the following file:

es.py

from elasticsearch import Elasticsearch
es = Elasticsearch()

I use it in places like tasks and views as follows:

import es
es.es.search(***********)

But to me it seems this would merely call es = Elasticsearch() each time, resulting in the connection being recreated. Is my approach correct?

Answer 1

Regardless of the choice of module and variable names ( es.es seems awkward), what your doing seems ok.

Elasticsearch() will be called only once, no matter how many times you import the module in the rest of your code.

I think you would want some way of reconnecting if the connection is lost, but that is another matter.

Answer 2

It should be correct as when you import es , es.py is executed and all the variables are initialized and added to the context. So, using es.es.search would use the already initialized variable es .

Answer 3

Just put this code in your settings.py file. Django will run it once and your connection will be instantiated once. And then import it from settings like this:

from django.conf import settings
settings.es