Flask environment ignored in config.py - flask

Question

I'm trying to build a basic flask app for learning purposes. everything flows smoothly, but there's an issue I don't understand. in my run.py file, I have the following line:
app.config.from_object('config.prodConfig')
This loads config.py in the root, which contains the following code:
class Config:
SECRET_KEY = '1234567890'
STATIC_FOLDER = 'static'
TEMPLATES_FOLDER = 'templates'
class devConfig(Config):
FLASK_ENV = 'development'
DEBUG = True
TESTING = True
class prodConfig(Config):
FLASK_ENV = 'production'
DEBUG = False
TESTING = False
my understanding is that Config contains a few "default" settings. devConfig and prodConfig are based on Config, so will always contain those values, but each will have different env, debug and testing value. though I don't get any errors and debug seems to be activated, when I run my instance of Flask it tells me I'm running in production, regardless of what I do.
* Serving Flask app "run" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: on
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
I'm not interested in setting the env variable in the terminal/environment, I know how to do that. what I'm interested in is why this doesn't work. after all, the FLASK_ENV directive is a valid one and it should load when instructed to.
What am I doing wrong?

Answer 1

With Chase's comment in mind, about not setting the FLASK_ENV in the app. Pass a dict of your configurations from your config.py and select the appropriate config based on the FLASK_ENV set outside your app, e.g. with a .env file.
config.py
class BaseConfig:
...
class DevConfig(BaseConfig):
...
class ProdConfig(BaseConfig):
...
configs = {"development": DevConfig, "production": ProdConfig}
app.py
import os
from flask import FLask
from config import configs
...
app.config.from_object(configs[os.environ.get("FLASK_ENV", "development")])