Missing method tkinter.Image._register

[TheLizzard]

Bug report

When tkinter get's a keyword argument, it tries to convert it to a string that tcl/tk can handle. The problem is that when a callable object is passed in as the value for a keyword argument, tkinter usually calls an internal _register method but it's missing from the Image class. Here in tkinter/__init__.py, tkinter tries to call self._register(v) but there is no method named _register in the Image class. There is a _register method for Misc and Variable but Image doesn't inherit from any of those. A minimal reproducible example:

import tkinter
root = tkinter.Tk()
tkinter.PhotoImage(height=print)

The expected error is: _tkinter.TclError: expected integer but got "140140827421696print" but it's throwing AttributeError: 'PhotoImage' object has no attribute '_register'.

The only time this bug would appear is when someone makes a mistake and calls PhotoImage or BitmapImage with a callable keyword parameter. So the only difference is the error message.

Your environment

The issue isn't environment dependant.

• CPython versions tested on: 3.10 but from the source code, it should be present in all 3.7+ versions of cpython.