示波器如何使用尝试和python中的块

Question

所以我对尝试和块的变量范围有些困惑。我的代码如何允许我在尝试块之外的变量，即使我没有在全球范围内分配它们。

while True:
        try:
            width = int(input("Please enter the width of your floor plan:n   "))
            height = int(input("Please enter the height of your floor plan:n   "))
        except:
            print("You have entered and invalid character. Please enter characters only. Press enter to continuen")
        else:
            print("Success!")
            break
print(width)
print(height)

，即使变量是在try块中定义的，它本身在段循环内，我也能够打印它们。他们不是本地的？

Answer 1

您需要比try更强大的东西来打开新的范围，例如def或class。您的代码具有类似于此版本的范围：

while True:
    width = int(input("Please enter the width of your floor plan:n   "))
    height = int(input("Please enter the height of your floor plan:n   "))
    if width <= 0 or height <= 0:
        print("You have entered and invalid character. Please enter characters only. Press enter to continuen")
    else:
        print("Success!")
        break
print(width)
print(height)

我假设您熟悉此范围。