list of Canvases contais only Nones

Laura Creighton lac at strakt.com
Mon Jan 27 15:56:31 EST 2003


> hello,
> 
> i am creating a frame with a lot of small canvases on it ant want to
> store the references in a list, but i get a list of nones instead.
> the frame gets created and shows all the canvases! so they are 
> definitely somewhere.
> 
> whats wrong with my code?
> 
> #my try:
> 
> canv_list = []
> root = Tkinter.Tk()
> for j in range(0,y_nr):
>      for i in range(0,x_nr):
>          canv_list.append(Tkinter.Canvas(root,
>                                          width = x_size,
>                                          height = y_size,
>                                          background = 'white',
>                                          border = 0
>                                          ).grid(row=j,column=i)
>                           )
> print canv_list
> 
> # the output of this code:
> 
> [None, None, None, None, None, None]
> 
> Thanks for help, Meinrad Recheis
> 
> -- 
> http://mail.python.org/mailman/listinfo/python-list

<anything>.grid, and <anything>.pack return None.  You need to make a
list of widget, row, col triplets, and then grid them all in a later
step.

Laura Creighton






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