text: from dotenv import load_dotenv
  import os
  load_dotenv()
  
  class Config(object):
      """Config base class
      This is the default configuration class for your app. You should
      `probably` not use this directly, instead extend this class with
       your custom config for different environments
      """
      DEBUG = False
      TESTING = False
      ENV = 'development'
      SECRET_KEY = os.getenv('SECRET_KEY', 'xxxx')
  
  
  class DevelopmentConfig(Config):
      """Development Config
      This extends the `Config` base class to store variables
      for development environments
      """
      DEBUG = True
      FLASK_APP = 'APP-DEV'
      SQLALCHEMY_TRACK_MODIFICATIONS = False
      SQLALCHEMY_DATABASE_URI = os.getenv('SQLALCHEMY_DATABASE_URI_DEV', 'sqlite:///dev.sqlite')
      PORT = os.getenv('PORT') or 2000
  
  class TestingConfig(Config):
      """Testing Config
         This extends the `Config` base class to store variables
         for testing environments
         """
      TESTING = True
      SQLALCHEMY_TRACK_MODIFICATIONS = False
      SQLALCHEMY_DATABASE_URI = os.getenv('SQLALCHEMY_DATABASE_URI_TESTING', 'sqlite:///test.sqlite')
  
  
  class StagingConfig(Config):
      """Staging Config
         This extends the `Config` base class to store variables
         for staging environments
  
         """
      pass
  
  
  class ProductionConfig(Config):
      """Production Config
         This extends the `Config` base class to store variables
         for production environments
  
         """
      ENV = 'production'
  
  key = Config.SECRET_KEY