flask_config.py

def create_flask_app(config=None):
    app = Flask(__name__)

    #: load default configuration
    app.config.from_object('diadem.settings')

    #: load environment configuration
    if 'DIADEM_CONF' in os.environ:
        app.config.from_envvar('DIADEM_CONF')

    #: load app sepcified configuration
    if config is not None:
        if isinstance(config, dict):
            app.config.update(config)
        elif config.endswith('.py'):
            app.config.from_pyfile(config)
    return app