How to get random value of attribute of Enum on each iteration?

I have created such Enum object:

class Gender(Enum):
    FEMALE = 'female'
    MALE = 'male'
    RANDOM = random.choice([FEMALE, MALE])

and i want to get really random value each time, but it does not work:

>>> class Gender(Enum):
...    MALE = 'male'
...    FEMALE = 'female'
...    RANDOM = choice([MALE, FEMALE])
... 
>>> Gender.RANDOM
<Gender.MALE: 'male'>
>>> Gender.RANDOM
<Gender.MALE: 'male'>
>>> Gender.RANDOM
<Gender.MALE: 'male'>
>>> Gender.RANDOM
<Gender.MALE: 'male'>

I have also tried use lambda, but it's looks not so good, although it works:

Gender.RANDOM()

Are there other way to get random values each time, without using lambda expressions?

We use this enum object as default value of the argument of the some method that's why it should be an attribute, not a function, because when we use Gender.FEMALE it is not a function, it's an attribute and Gender.RANDOM should be an attribute too:

def full_name(gender=Gender.FEMALE):
    ...


def full_name(gender=Gender.RANDOM):
    ...