Tkinter scrollbar for frame

Question

My objective is to add a vertical scroll bar to a frame which has several labels in it. The scroll bar should automatically enabled as soon as the labels inside the frame exceed the height of the frame. After searching through, I found this useful post. Based on that post I understand that in order to achieve what i want, (correct me if I am wrong, I am a beginner) I have to create a Frame first, then create a Canvas inside that frame and stick the scroll bar to that frame as well. After that, create another frame and put it inside the canvas as a window object. So, I finally come up with this:

from Tkinter import *  def data():     for i in range(50):        Label(frame,text=i).grid(row=i,column=0)        Label(frame,text="my text"+str(i)).grid(row=i,column=1)        Label(frame,text="..........").grid(row=i,column=2)  def myfunction(event):     canvas.configure(scrollregion=canvas.bbox("all"),width=200,height=200)  root=Tk() sizex = 800 sizey = 600 posx  = 100 posy  = 100 root.wm_geometry("%dx%d+%d+%d" % (sizex, sizey, posx, posy))  myframe=Frame(root,relief=GROOVE,width=50,height=100,bd=1) myframe.place(x=10,y=10)  canvas=Canvas(myframe) frame=Frame(canvas) myscrollbar=Scrollbar(myframe,orient="vertical",command=canvas.yview) canvas.configure(yscrollcommand=myscrollbar.set)  myscrollbar.pack(side="right",fill="y") canvas.pack(side="left") canvas.create_window((0,0),window=frame,anchor='nw') frame.bind("<Configure>",myfunction) data() root.mainloop() 

1. Am I doing it right? Is there better/smarter way to achieve the output this code gave me?
2. Why must I use grid method? (I tried place method, but none of the labels appear on the canvas.)
3. What so special about using anchor='nw' when creating window on canvas?

Please keep your answer simple, as I am a beginner.

Answer 1

Please note that the proposed code is only valid with Python 2

Here is an example:

from Tkinter import *   # from x import * is bad practice from ttk import *  # http://tkinter.unpythonic.net/wiki/VerticalScrolledFrame  class VerticalScrolledFrame(Frame):     """A pure Tkinter scrollable frame that actually works!     * Use the 'interior' attribute to place widgets inside the scrollable frame     * Construct and pack/place/grid normally     * This frame only allows vertical scrolling      """     def __init__(self, parent, *args, **kw):         Frame.__init__(self, parent, *args, **kw)                      # create a canvas object and a vertical scrollbar for scrolling it         vscrollbar = Scrollbar(self, orient=VERTICAL)         vscrollbar.pack(fill=Y, side=RIGHT, expand=FALSE)         canvas = Canvas(self, bd=0, highlightthickness=0,                         yscrollcommand=vscrollbar.set)         canvas.pack(side=LEFT, fill=BOTH, expand=TRUE)         vscrollbar.config(command=canvas.yview)          # reset the view         canvas.xview_moveto(0)         canvas.yview_moveto(0)          # create a frame inside the canvas which will be scrolled with it         self.interior = interior = Frame(canvas)         interior_id = canvas.create_window(0, 0, window=interior,                                            anchor=NW)          # track changes to the canvas and frame width and sync them,         # also updating the scrollbar         def _configure_interior(event):             # update the scrollbars to match the size of the inner frame             size = (interior.winfo_reqwidth(), interior.winfo_reqheight())             canvas.config(scrollregion="0 0 %s %s" % size)             if interior.winfo_reqwidth() != canvas.winfo_width():                 # update the canvas's width to fit the inner frame                 canvas.config(width=interior.winfo_reqwidth())         interior.bind('<Configure>', _configure_interior)          def _configure_canvas(event):             if interior.winfo_reqwidth() != canvas.winfo_width():                 # update the inner frame's width to fill the canvas                 canvas.itemconfigure(interior_id, width=canvas.winfo_width())         canvas.bind('<Configure>', _configure_canvas)   if __name__ == "__main__":      class SampleApp(Tk):         def __init__(self, *args, **kwargs):             root = Tk.__init__(self, *args, **kwargs)               self.frame = VerticalScrolledFrame(root)             self.frame.pack()             self.label = Label(text="Shrink the window to activate the scrollbar.")             self.label.pack()             buttons = []             for i in range(10):                 buttons.append(Button(self.frame.interior, text="Button " + str(i)))                 buttons[-1].pack()      app = SampleApp()     app.mainloop() 

It does not yet have the mouse wheel bound to the scrollbar but it is possible. Scrolling with the wheel can get a bit bumpy, though.

edit:

to 1)
IMHO scrolling frames is somewhat tricky in Tkinter and does not seem to be done a lot. It seems there is no elegant way to do it.
One problem with your code is that you have to set the canvas size manually - that's what the example code I posted solves.

to 2)
You are talking about the data function? Place works for me, too. (In general I prefer grid).

to 3)
Well, it positions the window on the canvas.

One thing I noticed is that your example handles mouse wheel scrolling by default while the one I posted does not. Will have to look at that some time.