from tkinter import *
window = Tk()
window.title("Aimtocode")
window.geometry('350x200')
lbl = Label(window, text="Hello")
lbl.grid(column=0, row=0)
def clicked():
lbl.configure(text="Welcome to Aimtocode")
btn = Button(window, text="Click Me", command=clicked)
btn.grid(column=1, row=0)
window.mainloop()