Python Simple GUI to run another script

simplegui.py

from Tkinter import *

root = Tk()

S = Label(root, text ="grupo:")
S.pack()

T = Text(root, height=2, width=30)


def callback():
    global T
    print "click!"
    import os
    os.system("python simple.py -g " + T.get(1.0, END))



T.pack()
T.insert(END, "51")

B = Button(root, height=2, width=30, text ="gerar", command=callback)
B.pack();

mainloop()