python - Tkinter: How to get frame in canvas window to expand to the size of the canvas? -

so i've been using canvas widget in tkinter create frame full of labels has scrollbar. working except frame expands size of labels placed in - want frame expand size of parent canvas.

this can done if use pack(expand = true) (which have commented out in code below) frame in canvas then scrollbar doesn't work.

here's appropriate bit of code:

        self.canvas = canvas(frame, bg = 'pink')         self.canvas.pack(side = right, fill = both, expand = true)          self.mailbox_frame = frame(self.canvas, bg = 'purple')          self.canvas.create_window((0,0),window=self.mailbox_frame, anchor = nw)          #self.mailbox_frame.pack(side = left, fill = both, expand = true)          mail_scroll = scrollbar(self.canvas, orient = "vertical",              command = self.canvas.yview)         mail_scroll.pack(side = right, fill = y)          self.canvas.config(yscrollcommand = mail_scroll.set)          self.mailbox_frame.bind("<configure>", self.onframeconfigure)       def onframeconfigure(self, event):         self.canvas.configure(scrollregion=self.canvas.bbox("all")) 

i've provided image colored frames can see i'm getting at. pink area canvas needs filling mailbox_frame (you can see scrollbar on right):

thanks

set binding on canvas <configure> event, fires whenever canvas changes size. event object can canvas width , height, , use resize frame.