old_contents: # configuration
  env_url = os.environ['DATABASE_URL']
  SQLALCHEMY_DATABASE_URI = env_url if env_url else 'postgresql://localhost/virchurro'
  DEBUG = True
  
new_contents: import os
  # configuration
  env_url = os.environ['DATABASE_URL']
  SQLALCHEMY_DATABASE_URI = env_url if env_url else 'postgresql://localhost/virchurro'
  DEBUG = True
  
subject: Fix import.