old_contents: import os
  
  #
  # Flask configuration
  #
  
  DEBUG      = True
  SECRET_KEY = 'secret'
  DEBUGGING_REQUESTS = False
  
  SQLALCHEMY_ENGINE_STR = os.environ.get('DATABASE_URL')
  
new_contents: import os
  
  #
  # Flask configuration
  # 
  
  DEBUG      = True
  SECRET_KEY = 'secret'
  DEBUGGING_REQUESTS = False
  
  
  heroku = os.environ.get('HEROKU', None)
  if heroku:
      SQLALCHEMY_ENGINE_STR = os.environ.get('DATABASE_URL')
  else:
      
      # 
      # DB Configuration
      # 
      USERNAME = 'labmanager'
      PASSWORD = 'labmanager'
      HOST     = 'localhost'
      DBNAME   = 'labmanager'
      
      ENGINE   = 'mysql' # or 'sqlite', 'postgresql', 'oracle'
      
      if ENGINE == 'mysql':
          SQLALCHEMY_ENGINE_STR = "mysql://%s:%s@%s/%s" % (USERNAME, PASSWORD, HOST, DBNAME)
          USE_PYMYSQL = True # or False, if MySQLdb is provided
      elif ENGINE == 'sqlite':
          SQLALCHEMY_ENGINE_STR = "sqlite:///%s.db" % DBNAME
      elif ENGINE == 'postgres':
          DRIVER = 'pg8000' # or 'psycopg2'
          SQLALCHEMY_ENGINE_STR = "postgresql+%s://%s:%s@%s/%s" % (DRIVER, USERNAME, PASSWORD, HOST, DBNAME)
      elif ENGINE == 'oracle':
          SQLALCHEMY_ENGINE_STR = "oracle://%s:%S@%s/%s" % (USERNAME, PASSWORD, HOST, DBNAME)
  
    # 
    # Not required: if you need to use a different domain name for external users
    # add this variable:
    # 
    # URL_ROOT = "http://my-domain:5000/"
    # 
  
subject: Add variables for heroku