If you try to insert an item into the treeview, give it a tuple of values for the "values" attribute, and one of those values has unbalanced braces, you'll get an error "unmatched open brace in list"

To reproduce:

import Tkinter as tk
import ttk

root = tk.Tk()
tree = ttk.Treeview(root)
tree.insert("","end",values=("one","two","bam! {"))

root.mainloop()