from pyfieldlib import *


class Human(metaclass=FieldMeta):
    _age = 19
    
    @fields
    def is_mammal(self):
        return True
    
    @fields
    def age(self):
        return Human._age

    @age.setter
    def age(self, value):
        Human._age = value


# get
print(Human.age)  # 19
print(Human.is_mammal)  # True

# set
Human.age = 20
print(Human.age)  # 20
Human.is_mammal = False  # Error