Tkinter: Understanding Columnspan effect on alignment

Question

I've been screwing around with some really basic grid commands in preparation for a project I want to do. I'm shooting for a 2x3 grid where:

• Row one would have a button that spans the entire three columns.
• Row two would have two buttons. One in column 2 and one in column 3. (or 1,2 assuming we start at 0, but whatever)

My first step was just to setup everything and see it working. Here's the main stuff:

b0 = Button(master, text = "Button 0")
b1 = Button(master, text = "Button 1")
b2 = Button(master, text = "Button 2")

b0.grid(row = 0, column = 0)
b1.grid(row = 1, column = 1)
b2.grid(row = 1, column = 2)

This worked as expected.

Three buttons aligned like I expect

Next I tried to make the top button span two columns by changing this:

b0.grid(row = 0, column = 0, columnspan=2)

And I got this...say what? Aligns row 1 and 2 on column 0

Ok so what if we span 3?

b0.grid(row = 0, column = 0, columnspan=3)

Yeah not what I expected... Centers Button 0, but doesn't maintain 3 columns properly

So what am I missing? How can I make Button 1 and 2 stay where they are in the first picture while expanding the Button0? Ideally Button0 would be a label, but it doesn't seem to matter for explanation purposes.

For what it's worth I was just trying to mimic a yes/no or ok/cancel box where I could name the buttons whatever I wanted. I didn't think the hard part would be aligning such a simple box.

What I was trying to mimic