How to find out height of a Canvas

[Tim Rowe]

How do I find out the height of a Tkinter Canvas? canvas.itemcget looks 
promising, but it needs two arguments (I get a Tcl error if I omit the 
second argument, or set it to None), and I can't find any documentation on 
what the second argument should be (or the first argument, for that 
matter; I'm assuming /that/ should be a string containing the name of the 
attribute).

TIA.