Hey Danny Thanks for the reply
Please let's talk about this more! *grin* I'm not sure if I'm following you, what I see here is a function inside other function and the first function returns its inside function, but how does it work? I don't know Scheme, but I know a little of C#, VB.NET, Pascal, QBasic and C++ 6.0 But I would prefer to talk in theory or in general. Thanks in advanced Alberto >From: Danny Yoo <[EMAIL PROTECTED]> >To: Alberto Troiano <[EMAIL PROTECTED]> >CC: tutor@python.org >Subject: Re: [Tutor] Minesweeper the return >Date: Mon, 18 Jul 2005 16:10:51 -0700 (PDT) > > > >On Mon, 18 Jul 2005, Alberto Troiano wrote: > > > > I'm trying to create the buttons dinamically (that's not a problem) the > > problem is wherever I click the hello function returns the last button I > > created. I know that the problem is in the lambda part and that the >variable > > i (the one I change the value within the for) but I don't how to fix it > > >Hi Alberto, > >Ah, this one comes up a bit. *grin* Let's look at the code: > >###### >for i in range(self.fil): > for j in range(self.col): > self.buttonmatrix[i][j]=Button(root,width=1,height=0, > command=lambda: self.hello(i,j)) >###### > >The issue is that all the dynamically generated functions are using the >same 'i' and 'j' variables. The big issue is that, in Python, for-loops >rebind the iterating variable name to different values, and that's what's >causing the issue. > > >Instead of using lambda directly, try something like this: > >###### >def make_hello(x, y): > def new_hello_function(): > self.hello(x, y) > return new_hello_function > >for i in range(self.fil): > for j in range(self.col): > self.buttonmatrix[i][j]=Button(root,width=1,height=0, > command=make_hello(i, j)) >###### > > >There's some subtle lexical-binding stuff going on there, so if you'd >like, we can talk about this more. If you're familiar with another >programming language with lexical scope (like Scheme), we can talk about >in terms of that language too. > > >Hope this helps! > >_______________________________________________ >Tutor maillist - Tutor@python.org >http://mail.python.org/mailman/listinfo/tutor Gaucho _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
