[Tkinter] should not be getting this exception...confused

[snippsat]

Post whole code as import is missing.
So to fix it i guess Buttons should be Button.

import tkinter as tk
from tkinter import Button

if __name__ == '__main__':
    root = tk.Tk()
    b = Button(root)
    root.mainloop()

I am trying to learn python class programming

Code over is not class programing,look at A Simple Hello World Program
So here use a class which is always advisable to use when doing GUI programming.