code:

class SleepingBeauty:
    def __init__(self):
        """ Create a sleeping beauty """
        self.num_observed_heads = 0

    def wake_up(self, coin_flip):
        """ The sleeper has awoken! """
        if coin_flip:
            self.num_observed_heads += 1

def one_trial(sleeping_beauty):
    """ Do one experiment """

    initial_flip = np.random.rand() >= 0.5
    sleeping_beauty.wake_up(initial_flip)

    if initial_flip:
        # Heads, no further flips
        return

    # Tails, run tuesday's experiment
    tuesday_flip = np.random.rand() >= 0.5
    sleeping_beauty.wake_up(tuesday_flip)


def main():
    """ Run a lot of experiments and tabulate sleeping beauty's experience """
    sleeper = SleepingBeauty()

    N = 100000
    for experiment_num in range(N):
        one_trial(sleeper)

    num_heads = sleeper.num_observed_heads
    percent_heads = float(num_heads) / N * 100.0
    print("Sleeping beauty saw the coin as heads {:}/{:} times ({:0.1f}%)".format(
        sleeper.num_observed_heads,
        N,
        percent_heads)
    )