tkinter: The deprecated trace variable command was removed from Tk 9.0 - tkinter still uses it.

[culler]

Bug report

Bug description:

The file tkinter/__init__.py contains the following code:

 def trace_variable(self, mode, callback):
 """Define a trace callback for the variable.

 MODE is one of "r", "w", "u" for read, write, undefine.
 CALLBACK must be a function which is called when
 the variable is read, written or undefined.

 Return the name of the callback.

 This deprecated method wraps a deprecated Tcl method that will
 likely be removed in the future. Use trace_add() instead.
 """
 # TODO: Add deprecation warning

 trace = trace_variable

The deprecated Tcl method was removed from Tcl 9.0, before the deprecation warning was added in tkinter. The trace_variable() and trace() methods still exist in both the current tkinter/__init__.py and the replacement which was included in PR #124112. Calling those methods with Tk 9.0 raises a TclError.

CPython versions tested on:

3.13

Operating systems tested on:

macOS

Linked PRs

• gh-127802: Schedule removal of legacy tkinter variable trace methods in 3.17 #152012
• [3.15] gh-127802: Schedule removal of legacy tkinter variable trace methods in 3.17 (GH-152012) #152186

[culler]

The deprecated Tcl trace variable command was a short cut for trace add variable. My suggestion would be to add the deprecation warnings to the trace and trace_variable methods of the Variable class, and also make those commands call the trace_add method. That way code which uses the deprecated methods will still work.

[serhiy-storchaka]

They will be removed in 3.17.

[terryjreedy]

idlelib/, turtledemo/, and turtle.py have no instances of trace_variable.