Creating Button arrays with different commands using Tkinter

[Harlin]

I have an array of Appnames. Let's say they are 'Monkeys', 'Cats',
'Birds'.

I would like create a button array with these:

---Start Code---
# Constructing and displaying buttons
for a in Appnames:
Button(root, text=a, command=lambda: self.OpenFile(a )).pack()

# Somewhere else I have this function defined within the class...
def OpenFile(self, AppName):
fh = open(AppName+". txt", 'r').read()
do something with fh

---End Code---

When I do this, whatever the last value a was is what the each button's
command option is. Does anyone know what I can do to differentiate each
button so that it has its own separate argument for self.OpenFile?

Thanks,

Harlin

[Fredrik Lundh]

Re: Creating Button arrays with different commands using Tkinter

"Harlin" <harlinseritt@y ahoo.com> wrote
[color=blue]
>I have an array of Appnames. Let's say they are 'Monkeys', 'Cats',
> 'Birds'.
>
> I would like create a button array with these:
>
> ---Start Code---
> # Constructing and displaying buttons
> for a in Appnames:
> Button(root, text=a, command=lambda: self.OpenFile(a )).pack()
>
> # Somewhere else I have this function defined within the class...
> def OpenFile(self, AppName):
> fh = open(AppName+". txt", 'r').read()
> do something with fh
>
> ---End Code---
>
> When I do this, whatever the last value a was is what the each button's
> command option is.[/color]

that's how lexical scoping works: you're passing in the value "a" has
when you click the button, not the value it had when you created the
lambda.
[color=blue]
> Does anyone know what I can do to differentiate each
> button so that it has its own separate argument for self.OpenFile?[/color]

bind to the object instead of binding to the name:

for a in Appnames:
Button(root, text=a, command=lambda a=a: self.OpenFile(a )).pack()

</F>

[Harlin Seritt]

Re: Creating Button arrays with different commands using Tkinter

Thanks Frederik. I knew it was not binding the way I intended to, but
just had no idea why or how to make it do so... thanks for the quick
lambda lesson :-)