所有Python都已填入，即使使用: radio_1.select？

Question

当我运行下面的代码时，即使我调用了difficulty1.select函数，我已经创建的所有Radiobuttons都会被填充。我在一本书中被告知，你可以调用difficulty1.select，然后只有你想要被选中的单选按钮才会被选中。

代码：

# Import Statements
from tkinter import *
import turtle
import tkinter.messagebox as box

# Windows Statements
window = Tk()
window.title("Options - CraftClash - Windows - Version 0.0.3 BETA")

# Widgets
difficultytitle = Label(window, text = "\n\nDifficulty:")
difficultyframe = Frame(window)
difficulty = StringVar()
difficulty1 = Radiobutton(difficultyframe, text = 'Easy', variable = difficulty)
difficulty2 = Radiobutton(difficultyframe, text = 'Normal', variable = difficulty)
difficulty3 = Radiobutton(difficultyframe, text = 'Hard', variable = difficulty)
difficulty1.select()

# Pack Statements
difficultytitle.pack(side = TOP)
difficulty1.pack(side = LEFT)
difficulty2.pack(side = LEFT)
difficulty3.pack(side = LEFT)
difficultyframe.pack(side = TOP)

# Sustain Window
window.mainloop()

谢谢!

Answer 1

.select()方法用于选择(或打开)单选按钮。在使用它之前，你还需要首先了解当你制作variable = StringVar()时，无线电按钮是如何独立工作的。我建议你在无线电按钮上读这个网页。引用一段话：

您可能会想，当控制变量从未被设置并且用户从未点击它们时，一组无线电按钮是什么状态？每个控件变量都有一个默认值: IntVar为0，DoubleVar为0.0，StringVar为“”。如果其中一个无线电按钮具有该值，则该无线电按钮将首先设置。如果没有任何无线电按钮的值选项与变量的值匹配，则所有的无线电按钮都将被清除。

因此，在您的代码中，没有定义值。让我们假设这3个按钮分别具有不同的值，如"Monday"、"Tuesday"和"Wednesday"。接下来，为名为“困难”的StringVar变量分配一些值。您需要在困难的情况下使用.set()方法。请注意，如果其值与无线电按钮值不同，则不会选择该无线电按钮。接下来，假设您允许difficulty = 'Tuesday'，您将看到difficulty2被选中。接下来，如果添加命令difficulty1.select()，您将看到困难2&3被取消选中，1被选中。对您的代码进行以下更改并尝试它。

# Widgets
difficultytitle = Label(window, text = "\n\nDifficulty:")
difficultyframe = Frame(window)
difficulty = StringVar()
difficulty.set('Tuesday')
difficulty1 = Radiobutton(difficultyframe, text = 'Easy', variable = difficulty,
                          value='Monday')
difficulty2 = Radiobutton(difficultyframe, text = 'Normal', variable = difficulty,
                          value='Tuesday')
difficulty3 = Radiobutton(difficultyframe, text = 'Hard', variable = difficulty,
                          value='Wednesday')
#difficulty1.select()