Tkinter StringVar tidak berfungsi

Try This One:

def ventanaPrincipal():
    top = Tkinter.Tk()
    var = Tkinter.StringVar()
    L1 = Tkinter.Label(top, text="Introduzca el nombre"+"\n"+ "completo del remitente:")
    E1 = Tkinter.Entry(top,textvariable = var)
    def buscar():
        buscarPorNombreYApellidos(var.get())

    B1 = Tkinter.Button(top, text ="Buscar", command = buscar)
    L1.pack(side = Tkinter.LEFT)
    B1.pack(side = Tkinter.RIGHT)
    E1.pack( side = Tkinter.RIGHT)
    top.mainloop()
SECRET MYSTERY