Python class 从具有列表属性的 tk.Frame 继承

Question

I'm in the process of teaching myself tkinter (objected-oriented style).

I want my class to produce a simple window with a single label in it. And I want the text for the label to come from an attribute, the first element of a list. This is a mockup made in Paint of what I would expect the window to look like:

But when I run the code below I get an error message ( TypeError: create() argument 1 must be str or None, not list ). I can't figure out how to pass 'my_list' so to create an instance of my class.

Thanks for any help!

import tkinter as tk

my_list = [222, 333, 444, 555]

class MyWindow(tk.Frame):
    def __init__(self, parent,  lst):
        self.lst = lst
        tk.Frame.__init__(self, parent)
        self.window_height = 200
        self.window_width = self.window_height * 2 
        canvas = tk.Canvas(self, width=self.window_width, height=self.window_height)
        canvas.pack()  
        label = tk.Label(self, text=str(self.lst[0]))       
        label.pack()
    
root= tk.Tk(my_list)
MyWindow(root).pack()
root.mainloop()

Answer 1

First, you cannot pass my_list to tk.Tk() .

Second, your MyWindow requires two parameters: parent and list (though you should name that second parameter something different).

Third, calling a geometry manager ( pack , grid , or place ) inline with the creation of the widget is a bad practice that should be avoided.

Here is how the final block of code should look like:

root= tk.Tk()
mywindow = MyWindow(root, my_list)
mywindow.pack()

This will end up with a window that has the label at the bottom. If you want it at the top, reverse the order that you pack the items in the frame and/or explicitly state where they should go:

label.pack(side="top", fill="x")
canvas.pack(side="bottom", fill="both", expand=True)