tkinter Treeview show accepts empty string

[melassa]

From the tcl tk doc of Treeview

Database Class: Show
A list containing ZERO or more of the following values, specifying which elements of the tree to display.

In Python 3.8 show='' display a Treeview without headings and tree column,
This is the pyi definition:

show: Literal["tree", "headings", "tree headings"] | tkinter._TkinterSequence[str] = ...,

[Akuli]

PR welcome!