entry is not defind error showing while i use a class to define the binding function

Question

screenshot of error

I am facing this error which shows in the screenshot, when I move my bind function into a class or another module

showing as entry is not defined.. it worked fine without a class

import tkinter 
from tkinter import *

root = tkinter.Tk()
root.wm_title("speed entering calculator")

class Methods1:
    i=0

    #function for enter
def entering(self,a):
        global i #to inform this function that i is global variable
        try:     # try and exception used to print message if error happen

            value1=int (entry1.get()) #entry1.get()is used to get values which entered in entry box
            value1=i + value1
            label1['text']=value1
            i=value1

        except ValueError as ve:
            print(f'only integer')



    entry1.delete(0, END) # used to clear entry box




ob=Methods1()











#creating canvas
canvas1 = tkinter.Canvas(root, height=400 , width=400, bg="black")
canvas1.pack()

#making entry box for values
entry1 = tkinter.Entry(root, justify="center", )
canvas1.create_window(200,140,height=100,width=100, window=entry1)

value = "the values should be shown here"
label1=Label(root, text =value, height=10) 
label1.pack()




#binding enter key as adding
root.bind('<Return>',ob.entering)






root.mainloop()

i am not really good at programming language. so I hope I could find a solution from here

Answer 1

The main problem was attempting to reference objects before they had been declared.

Rearranging the code solved that problem.

The other main problem was the importation method used for tkinter

Changing that to a standard form solved that.

Finally i in class needed to be changed to self.i

It now works.

import tkinter as tk

root = tk.Tk()
root.title("speed entering calculator")

#creating canvas
canvas1 = tk.Canvas(root, height = 400, width = 400, bg = "black")
canvas1.pack()

#making entry box for values
entry1 = tk.Entry(root, justify = "center")
canvas1.create_window(200, 140, height = 100, width = 100, window = entry1)

value = "the values should be shown here"
label1 = tk.Label(root, text = value, height = 10) 
label1.pack()

class Methods1:
    i = 0

    def entering(self, a):
        try:
            value1 = int(entry1.get()) 
            value1 = self.i + value1
            label1['text'] = value1
            self.i = value1
        except ValueError as ve:
            print(f'only integer')
        entry1.delete(0, tk.END) # used to clear entry box

ob = Methods1()

#binding enter key as adding
root.bind('<Return>', ob.entering)

root.mainloop()