all, I was debugging a very long script that I was not all that familiar with, and I was doing my familiar routine of being very careful in evaluating expressions to make sure that I didn't hit such statements as:
TypeError: unsupported operand type(s) for +: 'int' and 'str' anyways the script has a runtime of hours, so this was tedious work, and I hit one-too-many times where I missed a condition and had to start all over again. So that got me thinking: the main problem with exceptions and runtime errors is that they short-circuit the program context. You have this context, but you can't change it to avoid the failure; ie: with 1. aa = 'a' 2. bb = 1 + a 3. print bb you'll never get to line 3 if you go through line 2. If you are lucky you can catch it, modify aa to be an integer to continue, otherwise your only recourse is to start over again. So I was wondering if it would be possible to keep that context around if you are in the debugger and rewind the execution point to before the statement was triggered. so you could say: python script.py (Pdb) c then hit the exception, say: (Pdb) aa = 2 then run again (Pdb) c to work your way through the exception point. You could then fix the script inline in an editor. I can't emphasize exactly how much time and effort this would save. At best, debugging these types of issues is annoying, at worst it is excruciating, because they are sometimes intermittent and are not easily repeatable. Using RemotePdb or Pdb to attach to a long-running process and having the assurance that the underlying script won't die because of an inane coding error would do wonders for the reliability and integrity of scripting. so - is this possible? just from my experiments it doesn't look so, but perhaps there is a trick out there that would give this functionality.. if it isn't possible, how easy would it be to implement? Thanks much, Ed _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
