[split] New at Python programming

[heiner55]

Maybe this helps:

from tkinter import *
import random
import time

class Val:
  def __init__(self):
    pass
  def callback(self):
    E1.delete(0, END)
    E1.insert(0, random.randint(0,999))

root=Tk()
obj=Val()

L1 = Label(root,text="Number")
E1 = Entry(root)
B1 = Button(root,text="Click",command=obj.callback)

L1.grid(row=1,column=1)
E1.grid(row=1,column=2)
B1.grid(row=1,column=3)

root.mainloop()