Returning the index of an item clicked in a tkinter Listbox

Question

I'm trying to get tkinter to return the index of an item clicked in listbox. Here's my code.

def fileSelection(self):
    selection = listbox.curselection
    print(selection)

listbox.bind("<Button-1>", fileSelection)

Right now it prints

bound method Listbox.curselection of tkinter.Listbox object at 0x00320E30

no matter what item is clicked on. If I change the code to include a button like this:

button = Button(text=u"test", command=OnButtonClick)

def OnButtonClick():
    selection = listbox.curselection()
    print(selection)

and select the Listbox item, then click the button, it will print the index of the selected item, as expected, but that's an extra step I don't want.

Answer 1

def fileSelection(self):
    selection = listbox.curselection
    print(selection)

Looks like you forgot the parentheses.

def fileSelection(self):
    selection = listbox.curselection()
    print(selection)

Answer 2

According to effbot.org, polling the widget allows you to do on click updates.

self.current = None
self.listbox = Listbox(self)
self.listbox.pack()
self.poll()

def poll(self):
    now = self.listbox.curselection()
    if now != self.current:
        self.list_has_changed(now)
        self.current = now
    self.after(250, self.poll)

def list_has_changed(self, selection):
    print "selection is", selection