【Python基础】lpthw - Exercise 43 基本的面向对象分析和设计

1. A game

from sys import exit
from random import randint
from textwrap import dedent     # 使可以使用三引号型的字符串

# 具体实现了场景间的切换
class Engine(object):

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

    def play(self):
        current_scene = self.scene_map.opening_scene()  # 初始场景的类
        last_scene = self.scene_map.next_scene('finished')

        while current_scene != last_scene:
            next_scene_name = current_scene.enter()     # 返回一个场景的名字
            current_scene = self.scene_map.next_scene(next_scene_name)

        # 确保print出最后一个场景
        current_scene.enter()

# 各场景共有的父类
class Scene(object):

    def enter(self):
        pass

# 具体的每个场景，其中定义了一些说明和交互
class Death(Scene):

    quips = ["You died.", "Please try again.", "That's not very good."] # 类变量，可以通过类名调用

    def enter(self):
        print(Death.quips[randint(0,2)])
        exit(1)

class CentralCorridor(Scene):

    def enter(self):
        print("""
        You are met with some strange things.
        This is a locked room.
        It will be a good idea to leave right away.
        You see a Gothon blocking the door.
        Try to do something.
        """)
        action = input('>')
        if action == 'shoot!':
            return 'death'
        elif action == 'tell a joke!':
            return 'laser_weapon_armory'
        else:
            print("Nothing happened.")
            return 'central_corridor'


class LaserWeaponArmory(Scene):

    def enter(self):
        print("""
        This is the laser weapon armory.
        Destroy their weapon!
        Please enter the code.
        """)

        code = "123"
        guess = input('>')
        guesses = 0

        while guess != code and guesses < 5:
            print("That's not right!")
            guesses += 1
            guess = input('Try again >')

        if guess == code:
            print("Bingo! The weapon is destroyed!")
            return 'the_bridge'
        else:
            print("A bell rings and you are locked here to die!")
            return 'death'

class TheBridge(Scene):

    def enter(self):
        print("A bridge is in front of you and you see a huge bomb. ")
        action = input('>')

        if action == "throw it away":
            print("It exploded as you aprroached it. You died.")
            return 'death'
        elif action == "leave it behind":
            print("It seems nothing happened. You can safely pass it.")
            return 'escape_pod'
        else:
            return 'death'

class EscapeRod(Scene):

    def enter(self):
        print("""
        You finally make it to the escape rod.
        There are five ships in front of you.
        Which one do you want to take?
        """)
        num = input('>')
        correct_ship = '3'
        if num == correct_ship:
            print("You got on the ship. Everything seems getting on well. You won!")
            return 'finished'
        else:
            print("The ship is not working well. It exploded as take off!. You died!")
            return 'death'

class Finished(Scene):

    def enter(self):
        print("Congratulations! You successfully escaped from the ship!")
        return 'finished'

# 定义了各场景的名字，定义了进出场景的方法
class Map(object):

    scenes = {'central_corridor': CentralCorridor(),
              'laser_weapon_armory': LaserWeaponArmory(),
              'the_bridge': TheBridge(),
              'escape_pod': EscapeRod(),
              'death': Death(),
              'finished': Finished()
              }

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

    def next_scene(self, scene_name):
        nextScene = Map.scenes.get(scene_name)
        return nextScene                            # 根据传入名称返回一个场景的类

    def opening_scene(self):
        return self.next_scene(self.start_scene)    # 根据出发点名称返回出发点场景的类

a_map = Map("central_corridor")
a_game = Engine(a_map)
a_game.play()