Creating Button arrays with different commands using Tkinter

[Fredrik Lundh]

"Harlin" <harlinseritt at yahoo.com> wrote

>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.

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.

> Does anyone know what I can do to differentiate each
> button so that it has its own separate argument for self.OpenFile?

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>