text: # /instance/config.py
  
  import os
  
  
  class Config(object):
      """
          Parent configuration class.
      """
      DEBUG = False
  
  
  class DevelopmentConfig(Config):
      """
          Configurations for Development.
      """
      DEBUG = True
  
  
  class TestingConfig(Config):
      """
          Configurations for Testing
      """
      TESTING = True
      DEBUG = True
  
  class StagingConfig(Config):
      """
          Configurations for Staging.
      """
      DEBUG = True
  
  
  class ProductionConfig(Config):
      """
          Configurations for Production.
      """
      DEBUG = False
      TESTING = False
  
  
  app_config = {
      'development': DevelopmentConfig,
      'testing': TestingConfig,
      'staging': StagingConfig,
      'production': ProductionConfig,
  }