如何在不重复__init__中的setter方法的情况下定义属性？

Question

I'm trying to define a class which includes, through composition, an instance of faker.Faker() and random.Random() with the same value for their respective seed s:

import faker
import random

class DistanceRule(object):
    def __init__(self, seed=None):
        self.fake = faker.Faker()
        self.random = random.Random()
        self._seed = seed
        self.seed_fake_and_random()

    @property
    def seed(self):
        return self._seed

    @seed.setter
    def seed(self, seed):
        self._seed = seed
        self.seed_fake_and_random()

    def seed_fake_and_random(self):
        """Seed the instance's faker.Faker() and random.Random() with a
        single seed value.
        """
        self.fake.seed(self._seed)
        self.random.seed(self._seed)

so that running the following script

if __name__ == "__main__":
    d1 = DistanceRule(seed=5)
    print d1.random.randint(1, 10), d1.fake.name()
    d2 = DistanceRule(seed=12)
    d2.seed = 5
    print d2.random.randint(1, 10), d2.fake.name()

produces

7 Natalie Pope
7 Natalie Pope

This captures the desired behavior, namely that setting the seed property also re-seeds the instance's random data generators. The only thing that irks me is that there is code repetition in the __init__ and @seed.setter methods. Is there a more DRY way to do this?

Answer 1

Since you redefine the setter, you can call it at instance initialization:

def __init__(self, seed=None):
    self.fake = faker.Faker()
    self.random = random.Random()
    self.seed = seed