app_config[config_name] getting KeyError null value for flask environment
The first problem can be solved with a reasonable default:
config_name = os.getenv('FLASK_CONFIG') or 'default'or just os.getenv('FLASK_CONFIG', 'default'), where the meaning of the default can be set in config.app_config
app_config = { 'development': DevelopmentConfig, 'production': ProductionConfig, 'default': ProductionConfig}The app_config maps a name to an object with configuration. A reference ina string form is also allowed, but you can pass the object directly to .from_object):
app.config.from_object(app_config[config_name])The configuration data stored e.g. DevelopmentConfig must contain the data items as its attributes. It can be a class.