I try to adopt

My question is, how to keep that 'Button' at the verry bottom, while the bottom of treeview frame move up and down when I resize the main window.

CodePudding user response：

You need to:

• make self.tree to fill all available space by setting fill=tk.BOTH:

self.tree.pack(expand=True, fill=tk.BOTH)  # added fill=tk.BOTH

• disable expand of self.frameBT by removing expand=True:

self.frameBT.pack(fill=tk.X)  # removed expand=True