Tkinter Object show and hide

[Mauro]

Hy everyone,

Somebody can talk me if there are some option or function to hide and
show objects in Tkinter.

Example: 

---- Here is a object definition ----
first_obj = Button(root, text="Button 1")
first_obj.pack()

second_obj = Button(root, text="Button 2")
second_obj.pack()
---- Finish ----

I wanna know to hide the second object for example. But I need it in
Tkinter because I'm working in Windows.

Thanks to everyone...
Mauro