tkinter label and button grid placing-CodePudding

i have created window, in that window i put frame. Then i want to create two labels after them button widget. But, button widget appears upper than second label widget even though i put btn in row=2, and label2 in row=1. It 's hard for me to get why?

from  tkinter import *

window=Tk()
window.geometry('620x540 33 33')

var_pg=StringVar()
var_pg.set('Page 001 placeholder')

class lbl_custom(Label):
    def __init__(self,frame_window):
        super().__init__()
        self['width']=33
        self['font']='Segoe 12'

frame_submit=Frame(window)

lbl_page_num01=Label(frame_submit,width=33,textvariable=var_pg,font='Segoe 12')
lbl_page_num02=lbl_custom(frame_submit)
lbl_page_num02['text']='Page 002 placeholder'

btn_submit=Button(frame_submit,width=33,relief=RAISED,text='submit')

frame_submit.grid(row=0,column=0)
lbl_page_num01.grid(row=0,column=0)
lbl_page_num02.grid(row=1,column=0)

btn_submit.grid(row=2,column=0)

window.mainloop()

Now, it is for sure that. Every label widget which is created by class inheritance is going down than button nonetheless grid placeholder. But if I create it as Label() class it will be upper than button. Why it is so?

CodePudding user response：

You must pass the parent object when calling super, otherwise your custom object will always be a child of the root window.

class lbl_custom(Label):
    def __init__(self,frame_window):
        super().__init__(frame_window)
        #                ^^^^^^^^^^^^

You can pass other options as well, which will save you a couple lines of code:

class lbl_custom(Label):
    def __init__(self,frame_window):
        super().__init__(frame_window, width=33, font=("Segoe 12",))