Parameterized functions of no arguments?
Rotwang
sg552 at hotmail.co.uk
Fri Feb 11 00:26:18 EST 2011
On 11/02/2011 04:54, Rotwang wrote:
> Hi all
>
> Sorry if this is a dumb question, I would guess it's answered in an FAQ
> somewhere but I haven't been able to find anything that helps. I'm
> trying to use Tkinter to create a menu whose entries and corresponding
> commands depend on some list x. I want the menu options to be labelled
> by the elements of x, and upon selecting an option k I want my program
> to execute a function f(k). So I tried writing something that
> schematically looked like this:
>
> def f(k):
> [do something that depends on k]
>
> menu = Tkinter.Menu(master, tearoff = 0)
> for k in x:
> menu.add_command(label = str(k), command = lambda: f(k))
>
> The trouble is, whenever I open the menu and click on any entry k,
> instead of evaluating f(k) it always evaluates f(x[-1]). I've also tried
> this:
>
> menu = Tkinter.Menu(master, tearoff = 0)
> for k in x:
> def f():
> [do something that depends on k]
> menu.add_command(label = str(k), command = f)
Mmmmnngh, that obviously wasn't going to work. Here's something that
does work:
menu = Tkinter.Menu(master, tearoff = 0)
for k in x:
def f(j = k):
[do something that depends on j]
menu.add_command(label = str(k), command = f)
Still, I'd like to know if there's a more elegant method for creating a
set of functions indexed by an arbitrary list.
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