old_contents: import os
  
  class Config(object):
  
      DEBUG = False
      SECRET_KEY = os.urandom(30).encode('hex')
      TEMP_DIR = 'tmp'
      LIB_DIR = 'books'
  
      MONGO = {
          'HOST' : 'localhost',
          'PORT' : 27017,
          'DATABASE' : 'Alexandria'
      }
  
  class Debug(Config):
  
      DEBUG=True
  
new_contents: class Config(object):
  
      DEBUG = False
      SECRET_KEY = 'CHANGEME'
      TEMP_DIR = 'tmp'
      LIB_DIR = 'books'
  
      MONGO = {
          'HOST' : 'localhost',
          'PORT' : 27017,
          'DATABASE' : 'Alexandria'
      }
  
  class Debug(Config):
  
      DEBUG=True
  
subject: Use constant secret key for easier debugging