from  tkinter import *

def p():
    a =ef1.get()
    b=0
    for i in a:
        b+=int(i)
    r.configure(text = str(b))

root= Tk()
root.geometry('600x200+300+300')
ef1=Entry(width=100)
ef1.grid(column=2, row=0)
bf1=Button(text="Сума цифр", width=36, height=3, command=p)#.place(x=174,y=180)
bf1.grid(column=2,row=2)
r = Label(root, bg='blue', fg='yellow', width=80,height=2, text='')
r.grid(column=2, row=1)



root.mainloop()