学得小套路后，贵在用不同的程序去模仿和应用。

这是我模仿的丑小鸭版。

from sys import exit
from random import randint
from textwrap import dedent


# set class Scene 
class Scene(object):
    def enter(self):
        print("There is nothing.")
        exit(1)

# the transfer of scenes
class Engine(object):
    
    def __init__(self,scene_map):
        self.scene_map = scene_map
    
    # set the current_scene and the next scene, 
    # when the current_scene isn't equal to the last scene, the current scene is equal to the next_scene. 
    def play(self):
        current_scene = self.scene_map.opening_scene()
        last_scene = self.scene_map.next_scene('finished')

        while current_scene != last_scene:
            next_scene_name = current_scene.enter()
            current_scene = self.scene_map.next_scene(next_scene_name)

        current_scene.enter()

class Haystack(Scene):
    def enter(self):
        print(dedent(""" You are the ugly ducking. Your mummy duck had 7 eggs at haystack. Do you want to break out? """))
        action = input("out or no? > ")

        if action =="no":
            return 'death'
        elif action == "out":
            print("Congratulations! You come out, and you are big ugly ducklings.")
            return 'farm'
        else:
            print("Please input your choice.")
            return 'haystack'


class Farm(Scene):

    def enter(self):
        print(dedent(""" When they go to the farm, the animals mock at the ugly duckling and let you go away. What do you want? """))
        action = input("Go away or beat back? > ")
        if action == "beat back":
            print("The animals are angry, the they hit you.")
            return 'death'
        elif action == "go away":
            print("You are very sad and away from the farm.")
            return 'hole'
        else:
            print("Please input your choice.")
            return 'farm'

class Hole(Scene):
    def enter(self):
        print(dedent(""" You find a hole,but there is door. You should guess the right number. """))
        code = f"{randint(1,3)}{randint(1,3)}{randint(1,3)}"
        print(code)

        action = input("The code is : > ")
        guess = 1
        
        while action !=  code and guess < 3:
            print("Please try again!")
            action = input("The code is : > ")
            guess +=1

        if action == code:
            print("The door is open, you can survive winter until spring.")
            return 'river'
        elif action != code:
            print("Sorry, you are frozen to death.")
            return 'death'
        else:
            print("Please input your choice.")
            return 'hole'

class River(Scene):
    def enter(self):
        print(dedent(""" In spring, the ugly duckling went to the river, and a swan told that it is swan. Do you believe it? """))
        action = input("Believe or not? >")

        if action == "believe":
            print("It is truth. You are swan, you are beautiful, and you are so happy.")
            return 'finished'
        elif action == "not":
            print("Idiot! You miss a good chance, and you are so sad to death.")
            return 'death'
        else:
            print("Please input your choice.")
            return 'river'


class Death(Scene):
    def enter(self):
        death_way = ['You are an idiot',
                    'I have to say you should try again',
                    'You almost win',    
                    'Try again, you will win'
                    ]
        print(f"{death_way[randint(0,len(death_way)-1)]}")
        exit(1)

class Finished(Scene):
    def enter(self):
        print("You are the winner.")

# 建立地图辞典，以及各个地图之间的关系。
class Map(object):
    map_dict = {
   
        "haystack": Haystack(),
        "farm": Farm(),
        "hole": Hole(),
        "river": River(),
        "death": Death(),
        "finished": Finished()
    }

    def __init__(self, start_scene):
        self.start_scene = start_scene

    # get the value of dict, the value is the name of class.
    # the scene_name is the key of map_dict.
    def next_scene(self, scene_name):
        val = Map.map_dict.get(scene_name)
        return val

    def opening_scene(self):
        return self.next_scene(self.start_scene)

opening_map = Map("haystack")
player = Engine(opening_map)
player.play()




# The story
# You are the ugly ducking. The mummy duck had 7 eggs at haystack. 
# The gray egg cracked and the ugly duckling out. If you don't be out, you'll die in the egg.
# They went to the farm, and the animals mock at the ugly duckling go away. If you beat back, animals will hit you.
# The ugly duckling went to the hole, and survived winter. The hole had the code, and you must guess the right code,or you froze to death. 
# In spring, the ugly duckling went to the river, and a swan told that it is swan. 
# The ugly duckling looked into the water,and become happy. If you don't look into the water, you will sad to die.

# Word List
    # Map
    # Scene
    # Engine
    # Haystack
    # farm
    # forest
    # hole
    # river

# tree of concepts
    # Scene
        # Haystack
        # Farm
        # Forest
        # Hole
        # River
        # Death
    # Map
    # Engine