old_contents: import os
  basedir = os.path.abspath(os.path.dirname(__file__))
  
  
  class Config(object):
      """app wide configuration settings"""
      DEBUG = False
      CSRF_ENABLED = True
      SECRET = os.getenv('SECRET')
      SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URI')
  
  
  class DevelopmentConfig(Config):
      """Dev config settings"""
      DEBUG = True
  
  
  class TestingConfig(Config):
      """Testing config settings """
      TESTING = True
      SQLALCHEMY_TRACK_MODIFICATIONS = True
      SQLALCHEMY_DATABASE_URI = ('sqlite:///' + os.path.join(basedir,
                                                             'bucketlist.db'))
      DEBUG = True
  
  
  class StagingConfig(Config):
      """Staging config """
      DEBUG = True
  
  
  class ProductionConfig(Config):
      """ Production config """
      DEBUG = False
      TESTING = False
  
  
  app_config = {
      'development': DevelopmentConfig,
      'testing': TestingConfig,
      'production': ProductionConfig,
  
      'default': DevelopmentConfig
  }
  
new_contents: import os
  basedir = os.path.abspath(os.path.dirname(__file__))
  
  class Config(object):
      """app wide configuration settings. """
      DEBUG = False
      CSRF_ENABLED = True
      SECRET = os.getenv('SECRET')
      SQLALCHEMY_DATABASE_URI = os.getenv('DATABASE_URI')
  
  
  class DevelopmentConfig(Config):
      """Dev config settings. """
      DEBUG = True
      SQLALCHEMY_TRACK_MODIFICATIONS = False
  
  
  class TestingConfig(Config):
      """Testing config settings. """
      TESTING = True
      SQLALCHEMY_TRACK_MODIFICATIONS = True
      SQLALCHEMY_DATABASE_URI = ('sqlite:///' +
                                 os.path.join(basedir, 'bucketlist.db'))
      DEBUG = True
  
  
  class StagingConfig(Config):
      """Staging config. """
      DEBUG = True
  
  
  class ProductionConfig(Config):
      """ Production config. """
      DEBUG = False
      TESTING = False
  
  
  app_config = {
      'development': DevelopmentConfig,
      'testing': TestingConfig,
      'production': ProductionConfig,
      'staging': StagingConfig,
      'default': DevelopmentConfig
  }
  
subject: Add Flask config for staging, development, testing