如何修复 Atrrribute 错误“NoneType”对象没有属性“输入”

Question

我是学习 python 的新手，我在学习 python 3 中尝试了 ex43，但是我遇到了 Atrrribute Error 'NoneType' object has no attribute 'enter' in next_scene_name = current_scene.enter() 的问题。我该如何解决？

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


class Scene(object):

    def enter(self):
        print("This scene is not yet configured.")
        print("Subclass it and implement enter().")
        exit(1)


class Engine(object):
    
    def __init__(self, scene_map):
        self.scene_map = scene_map

    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)

        #be sure to print out the last scene
        current_scene.enter()

class Death(Scene):

    quips = [
        "You died. You kinda suck at this.",
        "Your mom would be proud... if she were smarter.",
        "Such a luser.",
        "I have a small puppy that's better at this.",
        "You're worse than your dad's jokes"

    ]

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

class CentralCorridor(Scene):

    def enter(self):
        print(dedent("""
            The Gothons of Planet Percal #25 have invaded your ship and
            destroyed your entire crew. You are the last surviving
            member and your last mission is to get the neutron destruct
            bomb from the Weapons Armory, put it in the bridge, and
            blow the ship up after gettin into an escape pod
            You're runnin down thhe central corridor to the Weapons
            Armory, when a Gothon jumps out, red scaly skin, dark grimy
            teeth, and evil clown costume flowing around his hate
            filled body. He's blocking te door to the Armory and
            about to pull a weapon to blast you.
            """))

        action = input("> ")

        if action == "shoot!":
            print(dedent("""
                Quick on the draw you yank ot your blaster and fire
                it at the Gothon. His clown costume is flowing and
                moving around is body, which throws off your aim.
                Your laser hits his costume but misses him entirely.
                his completely ruins his brand new costume his mother
                bought him, which make him fly into an insane rage
                and blas you repeatedly in the face until you are
                dead. Then he eats you
                """))
            return 'death'

        elif action == "dodge!":
            print(dedent("""
                Like a world class boxer you dodge, weave, slip and
                slide right as the Gothon's blaster cranks a laser
                past your head. In the middle of your artful dodge
                your foot slips and you bang your head on the metal
                wall and pass out. You wake up shortly after only to
                die as the Gothon stomps on your head and eats you.
                """))
            return 'death'

        elif action == "tell a joke":
            print(dedent("""
                Lucky for you they made you learn Gothon insults in
                the academy. You tell the one Gothon joke you know:
                Lbhe zbgure vf fb sng, jura fur fv fvgf nebhaq gur ubhfr,
                fur fvgf nebhaq gur ubhfr. The Gothon stops, tries
                not to laugh, then busts out laughing and can't move.
                While he's laughing you run up and shoot him squar
                the head putting him down, then jump through the
                Weapon Armory door.
                """))
            return 'laser_weapon_armory'

        else:
            print("DOES NOT COMPUTE!")
            return 'central_corridor'

class LaserWeaponArmory(Scene):

    def enter(self):
        print(dedent("""
            You do a dive roll into the Weapon Armory, crouch and scan
            the room for more Gothons that might be hiding. It's dead
            quiet, too quiet. You stand up and run to the far side of
            the room and find the neutron bomb in its container.
            There's a keypad lock on the box and you need the code to
            get the bomb out. If you get the code wrong 10 times then
            the lock closes forever and you can't get the bomb. The
            code is 3 digits.
            """))

        code = f"{randint(1,9)}{randint(1,9)}{randint(1,9)}"
        print(f"kode adalah {code}")
        guess = input("[keypad]")
        guesses = 0

        while guess != code and guesses < 10:
            print("BZZZZEDDD!")
            guesses += 1
            guess = input("[keypad]> ")

        if guess == code:
            print(dedent("""
                The container clicks open and the seal breaks, letting
                gas out. You grab the neutron bomb and run as fast as
                you can to the bridge where you must place it in the
                right spot.
                """))
            return 'the_bridge'
        else:
            print(dedent("""
                The lock buzzes one last time and then you hear a
                sickening melting sound as the mechanism is fused
                together. You decide to sit there, and finally the
                Gothons blow up the ship from their ship and you die.
                """))
            return 'death'



class TheBridge(Scene):

    def enter(self):
        print(dedent("""
            You burst onto the Bridge with the netron destruct bomb
            under your arm and surprise 5 Gothons who are trying to
            take control of the ship. Each of them has an even uglier
            clown costume than the last. They haven't pulled their
            weapons out yet, as they see the active bomb under your
            arm and don't want to set it off.
            """))

        action = input("> ")

        if action == "throw the bomb":
            print(dedent("""
                In a panic you throw the bomb at the group of Gothons
                and make a leap for the door. Right as you drop it a
                Gothon shoots you right in the back killing you. As
                you die you see another Gothon frantically try to
                disarm the bomb. You die knowing they will probably
                blow up when it goes off.
                """))
            return 'death'

        elif action == "slowly place the bomb":
            print(dedent("""
                You point your blaster at the bomb under your arm and
                the Gothons put their hands up and start to sweat.
                You inch backward to the door, open it, and then
                carefully place the bomb on the floor, pointing your
                blaster at it. You then jump back through the door,
                punch the close button and blast the lock so the
                Gothons can't get out. Now that the bomb is placed
                you run to the escape pod to get off this tin can.
                """))

            return 'escape_pod'
        else:
            print("DOES NOT COMPUTE")
            return "the_bridge"


class EscapePod(Scene):

    def enter(self):
        print(dedent("""
            You rush through the ship desperately trying to make it to
            the escape pod before the whole ship explodes. It seems
            like hardly any Gothons are on the ship, so your run is
            clear of interference. You get to the chamber with the
            escape pods, and now need to pick one to take. Some of
            them could be damaged but you don't have time to look.
            There's 5 pods, which one do you take?
            """))

        good_pod = randint(1,5)
        guess = input("[pod #]> ")


        if int(guess) != good_pod:
            print(dedent("""
                You jump into pod {guess} and hit the eject button.
                The pod escapes out into the void of space, then
                implodes as the hull ruptures, crushing your body into
                jam jelly.
                """))
            return 'death'
        else:
            print(dedent("""
                You jump into pod {guess} and hit the eject button.
                The pod easily slides out into space heading to the
                planet below. As it flies to the planet, you look
                back and see your ship implode then explode like a
                bright star, taking out the Gothon ship at the same
                time. You won!
                """))

            return 'finished'

class Finished(Scene):

    def enter(self):
        print("You won! Good job.")
        return 'finished'


class Map(object):

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

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

    def next_scene(self, scene_name):
        val = Map.scenes.get(scene_name)
        return val

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

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

Answer 1

NoneType 意味着您实际上拥有的不是您认为正在使用的任何类或对象的实例。这通常意味着上面的赋值或函数调用失败或返回了意外的结果。