On 07/07/2010 05:10 PM, Tambet wrote:
Hello!
I have such problem that:
* My console shows maximally x last lines, then truncates
* Error message takes 2 line
* In case of very big stack trace, there will be 2*x error lines
* In such case I do not see any debug output
In this case, it's about recursion:
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
and so on...
Depending on how far this goes up, you might just be able to change the
backlog your terminal emulator saves? that would allow you to scroll up.
If you can't do that, you should get a proper console.
Anyway, if you want to customise the traceback output, you can!
simply replace sys.excepthook with your own version.
http://docs.python.org/dev/py3k/library/sys.html#sys.excepthook
I think it should be instead:
File b2.py, line 124, in seek_solution [*repeated x times*]
solution = self.seek_solution(weight + U.gravity, len(test), test)
Getting big strack trace is most probable with functions calling
themselves - thus, long stack traces usually contain such repetitions.
As those functions might not call themselves directly, one cycle of
recursion might become four lines long, in such case:
Stack item 1: File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
Stack item 2: File b2.py, line 124, in seek_solution
solution = self.seek_solution(weight + U.gravity, len(test), test)
Stack item repetitions: [#1, #2] * x
This could simply enumerate stack items and then create formulas of
repetitions, like:
[[#1, #2] * 15, #3 * 15] * 3
If it shows each message written-out at least one and max two or three
times, but over that gives it an id and shows patterns of those instead,
it will be a lot better. I have, sometimes, gone through some four pages
of Java stack traces etc., but I think that having such long array of
errors does not make it more readable or simple - if you can see
everything in one page, then it's good enough for pondering. And
scrolling up and looking at output would be a nice feature ;) Especially
now, as I am going to raise recursion limit - this program would be
perfectly possible without relying on built-in loop constructions so
much, but I did it yesterday in such manner and it simply raised into
unmanageable complexity. Thus, now I am trying to encapsulate it's logic
into pieces, which maximize the use of Pythons overloads and
function-based iterators etc., but this makes error messages that long
when I do something wrong - and I can't even check if that was really
some mistake in code or just the recursion actually needs to be deeper
than I hoped.
Tambet
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