it_follows.py

#!/usr/bin/env python
import os
import random


class Follower:
    def __init__(self, starting_location, current_victim=None):
        # `starting_location` is a string representing a file system path.
        self.location = starting_location
        self.current_victim = current_victim
        self.victims = []

        if self.current_victim is not None:
            self.victims.append(self.current_victim)

    def kill(self):
        self.current_victim.dead = True

        try:
            self.current_victim = self.victims.pop()
        except IndexError:
            raise IndexError("We're all out of victims!")


class Victim:
    def __init__(self, starting_location):
        # `starting_location` is a string representing a file system path.
        self.location = starting_location
        self.dead = False

    def move(self):
        """Move to a random location in the file system."""
        pass

    def infect(self):
        return Victim(self.location)


def random_directory(root):
    return random.choice(os.listdir(root))


if __name__ == '__main__':
    first_victim = Victim(random_directory('~'))
    follower = Follower(random_directory('~'), first_victim)