将变量列表替换为不同函数中的不同变量

Question

我想用列表animals中的列表元素替换列表letters中的元素，其中as print(letters)将打印

["cat","dog","mouse","rabbit","hamster","duck","chicken","goose","hedgehog"]

如何将变量animals的值从函数newlist传递到函数main，然后替换main中变量的值

代码

def newlist():
    animals = ["cat","dog","mouse","rabbit","hamster","duck","chicken","goose","hedgehog"]
def main():
    letters = ["A","B","C","D","E","F","G","H","I"]
    print(letters)
main()  

Answer 1

请注意，必须调用Python中的函数，如果未指定任何值，它们将返回特定值或None。你知道吗

从Python Tutorial

The return statement returns with a value from a function. return without an expression argument returns None. Falling off the end of a function also returns None.

因此，您需要将函数newlist定义为

def newlist():
     animals = ["cat","dog","mouse","rabbit","hamster","duck","chicken","goose","hedgehog"]
     return animals       # RETURN THE LIST

这将按预期返回列表。你知道吗

要获取列表，需要调用可以使用newlist()完成的函数。因此main函数

def main():
    letters = ["A","B","C","D","E","F","G","H","I"]
    letters = newlist()   # CALL THE FUNCTION 
    print(letters)

现在，当您调用main时，您将得到预期的输出。你知道吗

---

不需要使用占位符创建单独的列表。你可以直接打电话给newlist，让你的列表准备好并开始工作。在这种情况下main函数将减少到

def main():
    letters = newlist()   # newlist returns a list, so call directly 
    print(letters)