I particularly like this bit:

  from returns.result import Result, Success, Failure
  
  def find_user(user_id: int) -> Result['User', str]:
      user = User.objects.filter(id=user_id)
      if user.exists():
          return Success(user[0])
      return Failure('User was not found')
  
  user_search_result = find_user(1)
  # => Success(User{id: 1, ...})
  
  user_search_result = find_user(0)  # id 0 does not exist!
  # => Failure('User was not found')  

https://returns.readthedocs.io/en/latest/pages/result.html