[Tkinter-discuss] Create Buttons on the fly

[Cameron Laird]

On Mon, Aug 31, 2009 at 11:40:07AM -0400, John Jack wrote:
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> I have a long list of objects, which I print to a GUI.  I want to filter
> this list, print the filtered list to the GUI, but maintain the ability to
> look at the previous lists.
> 
> My program currently takes the list (L1), prints it to a Listbox, and adds a
> button (B1) for the list.  Next, I filter the list, print the new filtered
> list (L2 subset of L1) to the same Listbox (removing the elements of L1 not
> in L2), and add an additional button for the new list. And so on...
> 
> How do I find a way to associate the old list L1 to the command for the
> button (B1)?  Note, I do not want to create a separate command for each
> button because I want to run an unlimited number of filters.  I need to have
> B1 linked to L1, B2 linked to L2, B3 linked to L3, etc.
> 
> Here is some relevant code (n.b., the whole project is much larger, so this
> is merely a snippet).
> 
> #n.b., L from the description above is all_entities.  So, L1 is
> all_entities[1], etc.
> #filter_group is an index tracking the current group to be filtered.
> 
>     #Filter the list
>     def search_entities(self):
>         tmp1 = askstring('Search Entity','Entity Type',initialvalue='gene')
>         filtered = []
>         #Create sublist
>         for ent in self.backend.all_entities[self.filter_group]:
>             if ent.etype.endswith("findthisstring"):
>                 filtered.append(ent)
> 
>         #Store sublist
>         self.backend.all_entities.append(filtered)
>         self.filter_group += 1
>         self.add_filter_button()
> 
>     def add_filter_button(self):
>         tmp = 'B%s' % self.filter_group
>         filt = Button(self,text = tmp,command=self.fill_listbox(self))
>         filt.grid(row=3,column=self.filter_group,sticky=E)
>         self.fill_listbox()
> 
>     def fill_listbox(self):
>        #clear listbox
>        if self.ent_listbox.size() > 0:
>             self.ent_listbox.delete(0,END)
>         #Restore list box
>         for ent in self.backend.all_entities[self.filter_group]:
>             self.ent_listbox.insert(END,ent.name)
> 
> The way my code exists now, I would need to modify the variable filter_group
> when I click a button.  How can I accomplish this?  How do I tell
> filter_group to be 1 if I click button 1 and 2 if I click button 2?
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The answer is implicit in <URL:
http://tkinter.unpythonic.net/wiki/Widgets/Button >, especially
in the section titled "Parameter-passing".  Is that enough of a
hint for you to reach the answer on your own?  Otherwise, I
expect one of us will make time over the next thirty hours or so
to provide an explicit coding.