More Tkinter menu problems

[Timothy R Evans]

"John Michelsen" <john.michelsen at gte.net> writes:

> >  self.menu.add_command(label = new_name,
> >   command = lambda temp_color = new_color:
> >   self.select_color(temp_color))
> >
> >but I get a Name Error on "self".  So now "self" is out of scope when
> >the menu call happens.
> 
> 
> try:
> self.menu.add_command(label = new_name,
>     command = lambda c=new_color, f=self.select_color: f(c))
> 
> John

Another possible way of implemented getting the same result, without
resorting to unreadable lambda expressions is to create a class
something like...

class Command:
    def __init__(self, func, *args, **kw):
        self.func = func
        self.args = args
        self.kw = kw

    def __call__(self, *args, **kw):
        args = self.args + args
        kw.update(self.kw)
        apply(self.func, args, kw)

then...

command = Command(self.select_color, new_color)

This costs one extra function call when it is used, but I think the
decrease in complexity of the expression make it worth it.

--
Tim Evans