user interface - Change command Method for Tkinter Button in Python

Question

I create a new Button object but did not specify the command option upon creation. Is there a way in Tkinter to change the command (onclick) function after the object has been created?

Answer 1

Though Eli Courtwright's program will work fine1, what you really seem to want though is just a way to reconfigure after instantiation any attribute which you could have set when you instantiated2. How you do so is by way of the configure() method.

from Tkinter import Tk, Button

def goodbye_world():
    print "Goodbye World!
Wait, I changed my mind!"
    button.configure(text = "Hello World!", command=hello_world)

def hello_world():
    print "Hello World!
Wait, I changed my mind!"
    button.configure(text = "Goodbye World!", command=goodbye_world)

root = Tk()
button = Button(root, text="Hello World!", command=hello_world)
button.pack()

root.mainloop()

1 "fine" if you use only the mouse; if you care about tabbing and using [Space] or [Enter] on buttons, then you will have to implement (duplicating existing code) keypress events too. Setting the command option through .configure is much easier.

2 the only attribute that can't change after instantiation is name.