Loading the file only once in application [closed]

Question

I have json data in a file and I want to load the file content only once when application is initiated instead of calling the loading file multiple times in class instances.

I created a config which loads on app init named REPOSITORY_CONFIG.

Then created a script with the method like this:

import json

CACHE = None

def get_repo_config():
    global CACHE
    with open('config.json') as config_json:
        CACHE = json.load(config_json)
    return CACHE

I have config.py

REPOSITORY_CONFIG = CACHE if CACHE else get_repo_config

This config is used in a class method like this:

import REPOSITORY_CONFIG

class Test():

  def check_config():
    config_data = REPOSITORY_CONFIG

Is there any other way to do this or I am not following right approach?

Answer 1

Module level code is only executed the first time a module is imported. Subsequent imports return the already imported module without rerunning the module level code. So use top level code to load the json file. Something like:

# config.py

# this module level code only gets run the first time the module is
# imported.
with open('config.json') as config_json:
    REPOSITORY_CONFIG = json.load(config_json)

# ... other config stuff ...

Then it can be used like:

import config

class Test():

    def check_config():
        config_data = config.REPOSITORY_CONFIG