Python 初学者Q：如何使用if/else缩进中声明的变量

在这一点上，我已经尝试了我能想到的一切。我正在尝试创建我的第一个游戏，玩家可以通过输入一个单词的答案来做出选择

当问题被孤立时，游戏就开始了。但是，如果我想创建一个将玩家重定向到游戏另一部分的决策（第7行通过river1变量直接到第10行），我会收到错误：NameError:name'river1'未定义，即使我在第7行定义了它

我认为这是因为它是在缩进中定义的。然而，我不知道如何修复它，并且仍然可以按要求工作。任何帮助都将不胜感激。谢谢

print("Welcome to Treasure Island! \nIts your mission to find the treasure.")
crossroads = input("You begin at a cross roads, do you go left or right? ").lower()
if crossroads == "left":
  enemies = input("You ran into enemies, attack? ").lower()
  if enemies == "no":
    print("You ran to the lake")
    river1 = input("You found a long river, it leads somewhere. Swim or wait? ").lower()
  else: 
    print("You were overpowered and died, game over")
if crossroads == "right":
  river1
  if river1 == "swim":
    print("You swam and drowned, Game over")
  else: 
    print("You found a boat")

---

对于只能在特定情况下定义的变量，您有两个选项。首先，您可以提前申报：

print("Welcome to Treasure Island! \nIts your mission to find the treasure.")
crossroads = input("You begin at a cross roads, do you go left or right? ").lower()
enemies = None
river1 = None
if crossroads == "left":
...

或者，您可以测试它们是否存在：

if crossroads == "right":
    if river1 and river1 == "swim":
...

---

解释程序的工作流程。我尝试了你的程序&得到了这个

C:\Users\LENOVO\Desktop\so>python try.py
Welcome to Treasure Island!
Its your mission to find the treasure.
You begin at a cross roads, do you go left or right? left
You ran into enemies, attack? no
You ran to the lake
You found a long river, it leads somewhere. Swim or wait? right

---

---

我相信您正在寻找的是如何重用代码。 使用函数

def river1_func():
    choice = input("You found a long river, it leads somewhere. Swim or wait? ").lower()
    if choice == "swim":
        print("You swam and drowned, Game over")
    else: 
        print("You found a boat")


if __name__ == "__main__":
    print("Welcome to Treasure Island! \nIts your mission to find the treasure.")
    crossroads = input("You begin at a cross roads, do you go left or right? ").lower()
    if crossroads == "left":
        enemies = input("You ran into enemies, attack? ").lower()
        if enemies == "no":
            print("You ran to the lake")
            river1_func()
        else: 
            print("You were overpowered and died, game over")
    if crossroads == "right":
        river1_func()
    
  

---

定义意味着将变量设置为一个值。如果没有执行这样的设置，则变量未定义。Ari，我认为程序逻辑中存在错误。若你们从上到下选择选项，那个么它是可以的，但若你们立即转到右边的纵横字谜，那个么这是程序第一次看到变量。您可以重新定义它或生成函数

river1 = ''

print("Welcome to Treasure Island! \nIts your mission to find the treasure.")
crossroads = input("You begin at a cross roads, do you go left or right? ").lower()
if crossroads == "left":
  enemies = input("You ran into enemies, attack? ").lower()
  if enemies == "no":
    print("You ran to the lake")
    river1 = input("You found a long river, it leads somewhere. Swim or wait? ").lower()
  else: 
    print("You were overpowered and died, game over")
if crossroads == "right":
  river1
  if river1 == "swim":
    print("You swam and drowned, Game over")
  else: 
    print("You found a boat")

def river1_func():
    choice = input("You found a long river, it leads somewhere. Swim or wait? ").lower()
    if choice == "swim":
        print("You swam and drowned, Game over")
    else: 
        print("You found a boat")


if __name__ == "__main__":
    print("Welcome to Treasure Island! \nIts your mission to find the treasure.")
    crossroads = input("You begin at a cross roads, do you go left or right? ").lower()
    if crossroads == "left":
        enemies = input("You ran into enemies, attack? ").lower()
        if enemies == "no":
            print("You ran to the lake")
            river1_func()
        else: 
            print("You were overpowered and died, game over")
    if crossroads == "right":
        river1_func()