(Also see the Button patterns).
To use a Checkbutton, you must create a Tkinter variable:
var = IntVar() c = Checkbutton(master, text="Expand", variable=var)
By default, the variable is set to 1 if the button is selected, and 0 otherwise. You can change these values using the onvalue and offvalue options. The variable doesn't have to be an integer variable:
var = StringVar() c = Checkbutton( master, text="Color image", variable=var, onvalue="RGB", offvalue="L" )
If you need to keep track of both the variable and the widget, you can simplify your code somewhat by attaching the variable to the widget reference object.
v = IntVar() c = Checkbutton(master, text="Don't show this again", variable=v) c.var = v
If your Tkinter code is already placed in a class (as it should be), it is probably cleaner to store the variable in an attribute, and use a bound method as callback:
def __init__(self, master): self.var = IntVar() c = Checkbutton(master, text="Enable Tab", variable=self.var, command=self.cb) c.pack() def cb(self, event): print "variable is", self.var.get()