Vladimir> This reminds me that some time ago I made an experimental Vladimir> patch for removing SET_LINENO. There was the problem of Vladimir> generating callbacks for pdb (which I think I solved somehow Vladimir> but I don't remember the details). I do remember that I had to Vladimir> look at pdb again for some reason. Is there any interest in Vladimir> reviving this idea? I believe you can get line number information from a code object's co_lnotab attribute, though I don't know the format. I think this should be sufficient to allow SET_LINENO to be eliminated altogether. It's just that there are places in various modules that predate the appearance of co_lnotab. Whoops, wait a minute. I just tried >>> def foo(): pass ... >>> foo.func_code.co_lnotab with both "python" and "python -O". co_lnotab is empty for python -O. I thought it was supposed to always be generated? -- Skip Montanaro | http://www.mojam.com/ skip@mojam.com | http://www.musi-cal.com/