Tkinter Canvas Problems

I'm trying to change the layering of Tkinter Canvas widgets. With most widgets you can force the widget above other widgets by using the lift method. However, if I try the same on a Canvas widget I get an error.

Error :

TypeError: tag_raise() got an unexpected keyword argument 'aboveThis'

An Example of my Problem :

import Tkinter as Tk


root = Tk.Tk()

w, h = 200, 200

a = Tk.Canvas(root, bg='red', width=w, height=h)
a.grid(column=0, row=0)

b = Tk.Canvas(root, bg='blue', width=w, height=h)
b.grid(co开发者_高级运维lumn=0, row=0)

a.lift(aboveThis=None)

root.mainloop()

If I do the same thing with Frame widgets, it works.

Example:

import Tkinter as Tk


root = Tk.Tk()

w, h = 200, 200

a = Tk.Frame(root, bg='red', width=w, height=h)
a.grid(column=0, row=0)

b = Tk.Frame(root, bg='blue', width=w, height=h)
b.grid(column=0, row=0)

a.lift(aboveThis=None)

root.mainloop()

The canvas lift() method is an alias for tag_raise(), which is used to raise not the canvas itself but entities within the canvas.

I found this comment within the Tkinter.py source code:

# lower, tkraise/lift hide Misc.lower, Misc.tkraise/lift,
# so the preferred name for them is tag_lower, tag_raise
# (similar to tag_bind, and similar to the Text widget);
# unfortunately can't delete the old ones yet (maybe in 1.6)

If you replace a.lift(aboveThis=None) with Tk.Misc.lift(a, aboveThis=None) then the canvas widget is raised correctly.

I came to this question because I was actually wanting to implement the equivalent of a tk statement like

canvas-pathName raise tagOrId ?aboveThis?

in order to raise individual canvas items to a particular z-position. For those interested in the same thing, I'll just post my realization (after a little head-scratching) that this can be done in Python quite easily:

canvasObject.tag_raise(tagOrId, tagOrId2)

The second argument here just gets incorporated into the tk command line, and is then interpreted as an "aboveThis" value.