PyWart: Exception error paths far too verbose
Ramchandra Apte
maniandram01 at gmail.com
Sat Jan 19 22:15:55 EST 2013
On Wednesday, 16 January 2013 15:23:55 UTC+5:30, Terry Reedy wrote:
> On 1/16/2013 12:59 AM, Rick Johnson wrote:
>
> >
>
> > Python needs to trim the path to the source file from which the
>
> > exception was caught and only display the relative path starting from
>
> > your personal library folder.
>
> >
>
> > For example. Say your personal library exists in:
>
> >
>
> > C:\users\user\documents\python\lib
>
> >
>
> > ...then there is no need to post THAT portion of the path EVERY
>
> > STINKING TIME! For instance, let's say a script at:
>
> >
>
> > C:\users\user\documents\python\lib\sound\effects\echo.py
>
> >
>
> > ...throws an error. What will we see?
>
> >
>
> > Traceback (most recent call last): File
>
> > "C:\users\user\documents\python\lib\sound\effects\echo.py", line N,
>
> > in BLAH
>
> >
>
> > Why do i need to see "C:\users\user\documents\python\lib" EVERY
>
> > time?
>
> >
>
> > Since all directories *BELOW* the directory that holds your personal
>
> > Python library are /superfluous/ when posting exceptions to stderr,
>
> > trimming this bloat can really help to make exception messages easier
>
> > to read.
>
> >
>
> > Traceback (most recent call last): File
>
> > "...\sound\effects\reverb.py", line XXX, in YYY
>
>
>
> I agree with the complaint and you may have the germ of a good idea. The
>
> problem is that for some tracebacks, paths jump all over the place
>
> rather than having a common prefix. Dealing with this might require
>
> preprocessing the entire traceback before iterating and printing each item.
>
>
>
> Are you are aware of
>
> '''
>
> sys.excepthook(type, value, traceback)
>
>
>
> This function prints out a given traceback and exception to sys.stderr.
>
>
>
> When an exception is raised and uncaught, the interpreter calls
>
> sys.excepthook with three arguments, the exception class, exception
>
> instance, and a traceback object. In an interactive session this happens
>
> just before control is returned to the prompt; in a Python program this
>
> happens just before the program exits. The handling of such top-level
>
> exceptions can be customized by assigning another three-argument
>
> function to sys.excepthook.
>
> '''
>
> This is how some apps and environments customize exception reporting
>
> (and logging). I believe some people also put a replacement in their
>
> site module.
>
>
>
> >>> import sys; sys.excepthook
>
> <built-in function excepthook>
>
>
>
> I expect the default, excepthook, is something like
>
>
>
> def excepthook(typ, value, traceback):
>
> print('Traceback (most recent call last):', file=sys.stderr)
>
> for item in traceback:
>
> print(format_tb_item(item), file=sys.stderr)
>
> print('{}: {}'.format(typ.__name__, value), file=sys.stderr)
>
>
>
> (or the equivalent with sys.stderr.write)
>
>
>
> What you want to change is format_tb_item (possibly, as I said, after
>
> scanning traceback before the print loop). If you come up with something
>
> nice, I would like to see it.
>
>
>
> The only thing special that IDLE does now is to color the text red. I
>
> should sometime see how that is done. (Being able to doubleclick on an
>
> item and have IDLE open an edit window at the specified line would be
>
> really nice!)
>
>
>
> --
>
> Terry Jan Reedy
Right-click the file in the traceback and there is an "Go to file/line" option.
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