new_contents: from django.core.exceptions import ImproperlyConfigured
  
  from .settings import *
  
  
  def get_env_variable(var_name):
      """
      Get the environment variable or return exception.
      """
      try:
          return os.environ[var_name]
      except KeyError:
          error_msg = 'Set the %s environment variable' % var_name
          raise ImproperlyConfigured(error_msg)
  
  DEBUG = False
  
  ALLOWED_HOSTS = ['tictactoe.zupec.net']
  
  SECRET_KEY = get_env_variable('SECRET_KEY')
  
  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.postgresql_psycopg2',
          'NAME': get_env_variable("DATABASE_NAME"),
          'USER': get_env_variable("DATABASE_USER"),
          'PASSWORD': get_env_variable("DATABASE_PASSWORD"),
          'HOST': get_env_variable("DATABASE_HOST"),
          'PORT': '5432',
      },
  }
  
  
subject: Add production settings.