config.py

# Python
from os import getenv


class Config:
    APP_PORT = int(getenv('APP_PORT'))
    DEBUG = eval(getenv('DEBUG').title())


class DevelopmentConfig(Config):
    FLASK_ENV = 'development'
    DEBUG = True

class TestingConfig(Config):
    FLASK_ENV = 'testing'
    TESTING = True

config = {
    'development': DevelopmentConfig,
    'testing': TestingConfig,
    'default': DevelopmentConfig
}