Fair Coin from Unfair Coin - Groupon Interview Question

extractor.py

import random


def bernoulli_process(p):
    if p > 1.0 or p < 0.0:
        raise ValueError("p should be between 0.0 and 1.0.")

    while True:
        yield random.random() < p


def von_neumann_extractor(process):
    while True:
        x, y = process.next(), process.next()
        if x != y:
            yield x