new_contents: import os
  
  
  class Config:
      # Pull SECRET_KEY from environment variable, if not set use default one
      SECRET_KEY = os.environ.get('SECRET_KEY')
      SQLALCHEMY_COMMIT_ON_TEARDOWN = True
      SQLALCHEMY_TRACK_MODIFICATIONS = True
  
      MAIL_SERVER = 'smtp.googlemail.com'
      MAIL_PORT = 587
      MAIL_USE_TLS = True
      MAIL_USERNAME = os.environ.get('MAIL_USERNAME')
      MAIL_PASSWORD = os.environ.get('MAIL_PASSWORD')
      WEATHER_APP_MAIL_SUBJECT_PREFIX = '[WEATHER_APP]'
      WEATHER_APP_MAIL_SENDER = 'WEATHER_APP Admin <weather_app@example.com>'
      WEATHER_APP_ADMIN = os.environ.get('WEATHER_APP_ADMIN')
  
      @staticmethod
      def init_app(app):
          pass
  
  
  class DevelopmentConfig(Config):
      DEBUG = True
      SQLALCHEMY_DATABASE_URI = os.environ.get('WEATHER_APP_DEV_DB') or 'postgresql://tom:tom@localhost/weather_app'
  
  
  class TestingConfig(Config):
      TESTING = True
      SQLALCHEMY_DATABASE_URI = os.environ.get('WEATHER_APP_TEST_DB')
  
  
  class ProductionConfig:
      SQLALCHEMY_DATABASE_URI = os.environ.get('WEATHER_APP_PROD_DB')
  
  
  config = {
      'default': DevelopmentConfig,
  
      'development': DevelopmentConfig,
      'testing': TestingConfig,
      'production': ProductionConfig
  }
  
subject: Add configuration