Hi, i'm using odoo v11.

I was wondering if it's possible (and, if so, which is the most standard way) to define global variables that may be accessible everywhere in the python side of my odoo deployement.

My company is planning to release several odoo deployements for different customers, but most of the functionalities would still be the same across the different deployements. 

I'd like to code my custom modules in the most general way possible, delegating the customer-specific features to server-side conditions like

if(is_feature_xyz_active):
    #do some nifty stuff

where 'is_feature_xyz_active' is a global variable saved somewhere, whose value will be set according to the requests of the specific customer.

Where should I save those variables, and how should I access them?

Thank you very much in advance.