Nick Coghlan added the comment: The same way the dis module does: by looking at the names listed in the various code object attributes.
If it's listed in co_cellvars, then it's a local variable in the current frame that's in a cell because it's part of the closure for a nested function. If it's listed in co_freevars, then it's a nonlocal closure reference. Otherwise, it's a regular local variable that just happens to be holding a reference to a cell object. So if all we did was to put the cell objects in the frame.f_locals dict, then trace functions that supported setting attributes (including pdb) would need to be updated to be cell aware: def setlocal(frame, name, value): if name in frame.f_code.co_cellvars or name in frame.f_code.co_freevars: frame.f_locals[name].cell_contents = value else: frame.f_locals[name] = value However, to make this more backwards compatible, we could also make it so that *if* a cell entry was replaced with a different object, then PyFrame_LocalsToFast would write that replacement object back into the cell. Even with this more constrained change to the semantics frame.f_locals at function level, we'd probably still want to keep the old locals() semantics for the builtin itself - that has lots of string formatting and other use cases where having cell objects suddenly start turning up as values would be surprising. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue30744> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com