Write Python GUI program that takes input string and change letter to upper case when a button is pressed.
from tkinter import *
def volumesphere():
label_text.set(string.get().upper())
window = Tk()
label_text=StringVar();
Label(window, text="Enter String:").grid(row=0)
Label(window, text="Uppercase = ").grid(row=3)
result=Label(window, text="",
textvariable=label_text).grid(row=3,column=1)
string = Entry(window)
string.grid(row=0, column=1)
b = Button(window, text="Calculate",
command=volumesphere)
b.grid(row=0, column=2,columnspan=2, rowspan=2, padx=5, pady=5)
mainloop()
