from tkinter import *
#create window
root= Tk()
#modify root windows
root.title("Simple GUI")
root.geometry("300x200")

app=Frame(root)
app.grid()

label=Label(app, text="This is a label")
label.grid()

button1= Button(app, text="Button")
button1.grid()
button2= Button(app)
button2.grid()
button2.configure(text="Button2")

button3=Button(app)
button3.grid()
button3['text']="Show up"



#kick off event loop
root.mainloop()