How to correctly set the list of possible values ​​for an object attribute?

Question

Python

How to correctly set the list of possible values ​​for an object attribute?
For example:
1) there is a Task class,
2) there is an instance of the task class,
3) it has a task.priority attribute,
4) which should take the values ​​options = ['low', 'medium', 'high'].
As a result, I should be able to:
1) set task.priority = 'low'
2) get an error if I try to set task.priority = 'something else'
Alternatively, you can check in the class constructor if value in options , or is there a more correct one way to do it?

Answer 1

class Task(object):
    
    @property
    def priority(self):
        return self._priority

    @priority.setter
    def priority(self, value):
        if value not in ('low', 'high', 'medium'):
            raise ValueError('Incorrect priority value')
        self._priority = value

Answer 2

Pass the value of the variable not by assigning a value, but through the set_priority method, in which the check will be carried out. For example like this:

class Task():
    def set_priority(self, priority):
        if priority in ['low', 'medium', 'high']:
            # Делаем что-то хорошее, например
            self.priority = priority
        else:
            # Выводим ошибку