Python文本类游戏全局变量赋值报错求助：local variable referenced before assignment

错误原因 #

在forestscene函数里，你对user_input执行了赋值操作（user_input = input("> ")），Python会默认把它当成局部变量。但while user_input not in commands这行代码在赋值前就引用了它，所以触发"local variable referenced before assignment"错误。你之前加global只解决了首行引用问题，但场景切换后程序结束，是因为调用roadscene()或wolfscene()后，当前函数的循环没有继续，且其他场景函数没有处理输入循环，导致执行完就退出了。

方案1：正确使用global关键字并完善循环逻辑 #

在函数开头声明global user_input，确保函数内操作的是全局变量，同时给每个场景函数都加上输入循环，保证切换场景后能正常交互。

修改后的代码示例：

print("story text removed for length")
light = False
killer_location = 2
wolves = True
commands = ["n", "S", "E", "W", "north", "south", "east", "west", "look","use","pick up", "attack","jump","throw"]
inventory = ["testinventoryobjectforarray"]
user_input = ">"

def forestscene():
    global user_input  # 声明使用全局变量
    print("You are in a small clearing in the woods. Tall trees in every direction.")
    print("You see a dirt road to the north of you. ")
    
    while True:  # 用无限循环维持交互
        user_input = input("> ")
        # 先判断输入是否合法
        if user_input.lower() not in [cmd.lower() for cmd in commands]:
            print("...")
            continue
        # 处理合法命令
        if user_input.lower() in ["n", "north"]:
            roadscene()
        elif user_input.lower() in ["s", "south"]:
            wolfscene()
        elif user_input.lower() in ["e", "east"]:
            print("The trees are too dense and it's too dark to proceed further east.")

def roadscene():
    global user_input
    print("You're on a dirt road. The forest stretches out behind you.")
    while True:
        user_input = input("> ")
        if user_input.lower() in ["s", "south"]:
            forestscene()  # 返回森林场景
            break
        # 可添加其他道路场景的命令逻辑

def wolfscene():
    global user_input
    print("A pack of wolves surrounds you!")
    while True:
        user_input = input("> ")
        if user_input.lower() in ["n", "north"]:
            forestscene()
            break
        elif user_input.lower() in ["attack"]:
            print("You fight off the wolves and return to the clearing.")
            forestscene()
            break

forestscene()

方案2：用类封装游戏状态（推荐） #

全局变量多了会让代码越来越难维护，用类来统一管理所有游戏状态（位置、物品、输入逻辑等），后续扩展新场景或功能会更方便。

代码示例：

class TextGame:
    def __init__(self):
        self.light = False
        self.killer_location = 2
        self.wolves = True
        self.commands = ["n", "S", "E", "W", "north", "south", "east", "west", "look","use","pick up", "attack","jump","throw"]
        self.inventory = ["testinventoryobjectforarray"]
        self.current_scene = "forest"  # 记录当前场景

    def run(self):
        # 主循环，根据当前场景调用对应函数
        while True:
            if self.current_scene == "forest":
                self.forestscene()
            elif self.current_scene == "road":
                self.roadscene()
            elif self.current_scene == "wolf":
                self.wolfscene()

    def forestscene(self):
        print("You are in a small clearing in the woods. Tall trees in every direction.")
        print("You see a dirt road to the north of you. ")
        user_input = input("> ")
        # 判断输入合法性
        if user_input.lower() not in [cmd.lower() for cmd in self.commands]:
            print("...")
            return
        # 切换场景或执行动作
        if user_input.lower() in ["n", "north"]:
            self.current_scene = "road"
        elif user_input.lower() in ["s", "south"]:
            self.current_scene = "wolf"
        elif user_input.lower() in ["e", "east"]:
            print("The trees are too dense and it's too dark to proceed further east.")

    def roadscene(self):
        print("You're on a dirt road. The forest stretches out behind you.")
        user_input = input("> ")
        if user_input.lower() in ["s", "south"]:
            self.current_scene = "forest"
        # 可添加更多道路场景的交互逻辑

    def wolfscene(self):
        print("A pack of wolves surrounds you!")
        user_input = input("> ")
        if user_input.lower() in ["n", "north"]:
            self.current_scene = "forest"
        elif user_input.lower() in ["attack"]:
            print("You fight off the wolves and return to the clearing.")
            self.current_scene = "forest"

if __name__ == "__main__":
    print("story text removed for length")
    game = TextGame()
    game.run()

内容的提问来源于stack exchange，提问作者KniteRite