python-3.x - 如何停止我的功能？

Question

当满足条件时，如何让我的功能停止？
例如在我下面的代码中，当用户输入:“q”(退出)时，我希望我的函数简单地停止。
我试过使用“break”语句，但它不起作用。

def main():
    shape = input("Enter shape to draw (q to quit): ").lower()
    while shape != 'triangle' and shape != 'square' and shape != 'q':
            print("Unknown shape. Please try again")
            shape = input("Enter shape to draw (q to quit): ").lower()
    if shape == "q":
        print("Goodbye")  
        break #Python not happy with the indentation.

def get_valid_size():
    size = int(input("Enter size: "))
    while size < 1:
        print("Value must be at least 1")
        size = int(input("Enter size: "))
main()
get_valid_size()

当我运行它时，它执行:
Enter shape to draw (q to quit): q
Goodbye
Enter size:
我不希望它要求尺寸。

Answer 1

return 将退出一个函数，将控制权返回给最初调用该函数的任何人。如果你想了解更多，谷歌的短语是“退货声明”。
break将退出循环，as described here .

尝试类似:

def main():
    shape = input("Enter shape to draw (q to quit): ").lower()
    while shape != 'triangle' and shape != 'square' and shape != 'q':
            print("Unknown shape. Please try again")
            shape = input("Enter shape to draw (q to quit): ").lower()
    if shape == "q":
        print("Goodbye")  
        return
    get_valid_size()

def get_valid_size():
    size = int(input("Enter size: "))
    while size < 1:
        print("Value must be at least 1")
        size = int(input("Enter size: "))
main()