Feature: Support `filename:function` syntax for pdb break and clear command

Feature or enhancement

Proposal:

Currently, pdb's break command supports filename:lineno or just function (in the current context or imported modules). However, it does not support the filename:function syntax.

Attempting to use break filename:function usually results in a Error because pdb expects the part after the colon to be a line number.

main.py:

def foo():
    pass

bash-5.3# ./python -m pdb main.py
> /workspaces/cpython/main.py(1)<module>()
-> def foo():
(Pdb) b main:foo
*** Bad lineno: foo

This syntax is useful for specifying a function in a specific file, especially to disambiguate if multiple files have the same function name, or if the file hasn't been loaded yet but the user wants to be explicit.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-142470

Beginne mit der bestehenden Verarbeitung der break- und clear-Befehle von pdb und vergleiche dabei die Pfade zur Auflösung von filename:lineno und function. Reproduziere das main.py-Beispiel mit b main:foo und überprüfe anschließend, dass filename:function funktioniert, ohne die bestehenden Formen zu beeinträchtigen; das Issue verweist auf den verknüpften PR gh-142470.