如何解决Python SyntaxError: 'break' outside loop报错并终止外层循环

• break 语法规则限制：Python 中break关键字只能直接作用于其所在层级的for/while循环块，无法跨函数调用生效，你将break写在独立的函数内部，自然会触发SyntaxError: 'break' outside loop报错
• 全局变量修改错误：你在函数内部赋值的game_on = False是函数局部变量，并不会修改外部控制循环的全局game_on变量，就算去掉break也无法终止循环

保持你现有的函数拆分结构不变，将校验函数改为返回布尔值标识是否触发结束条件，在循环外层根据返回值执行break即可，既保证代码可复用，也符合语法规则。
主要修改点如下：

• 移除了函数内部的break和局部game_on赋值逻辑，校验到胜负条件后返回True，否则返回False
• checkWin通过逻辑或判断两个校验函数的结果，只要任意一个触发结束条件就返回True
• 循环内每次调用checkWin后判断返回值，符合条件就执行break终止循环，满足结束程序的需求

# Configures Hero class
class Hero():
    def __init__(self, name, hp, atk, defence):
        self.name = name
        self.hp = hp
        self.atk = atk
        self.defence = defence

    def attackAction(self, enemy):
        print(self.name + " attacks " + enemy.name + "!")
        enemy.defenceAction(self, self.atk)

    def defenceAction(self, enemy, atk_enemy):
        print(self.name + " defenced against " + enemy.name + "'s attack.")
        calculatedAtk = abs(atk_enemy/self.defence)
        self.hp -= calculatedAtk
        print(self.name + " lost " + str(calculatedAtk) + "HP!")
        print(self.name + " now has " + str(self.hp) + " remaining.")


#Archer and Wizard attributes
archer = Hero("Archer", 20, 2, 2)
wizard = Hero("Wizard", 15, 3, 1)

# Checks Wizard's HP
def checkWizHP():
    if wizard.hp <= 0:
        print(wizard.name + " has died.")
        print("Archer has won!")
        return True
    return False

# Checks Archer's HP
def checkArchHP():
    if archer.hp <= 0:
        print(archer.name + " has died.")
        print("Wizard has won!")
        return True
    return False

# Checks winning condition
def checkWin():
    return checkWizHP() or checkArchHP()

game_on = True

while game_on:
    archer.attackAction(wizard)
    print("\n")
    if checkWin():
        break
    wizard.attackAction(archer)
    if checkWin():
        break

内容的提问来源于stack exchange，提问作者nico