[TIP] Annotated tracebacks

Robert Collins robertc at robertcollins.net
Sun Oct 19 16:29:24 PDT 2014

On 20 October 2014 12:10, Chris Jerdonek <chris.jerdonek at gmail.com> wrote:
> On Sat, Oct 18, 2014 at 2:52 AM, Robert Collins
> <robertc at robertcollins.net> wrote:
>> testtools just had this bug opened on it:
>> https://github.com/testing-cabal/testtools/issues/111
>> Which has a few contributing issues but one in particular is that
>> simple tracebacks don't give you the value of variables in parameters,
>> nor of local variables in the trace.
>> I'm aware of the implementation details that can make showing those
>> values fraught (since __str__ and __repr__ can execute arbitrary
>> code), but I thought I'd do a straw poll here and see who supports the
>> idea of the traceback module itself offering to format such things
>> (e.g. via a locals=False parameter to format_list and friends), which
>> testtools could then backport to older pythons, and use itself to do
>> this.
> A lot of times, it's the value of variables in frames other than the
> final frame that are needed to troubleshoot an issue.  Is the proposal
> only to address variables in the final frame?  It seems like if
> something will be done in the stdlib and the enhancement is limited to
> the final frame, then the proposed API should be chosen so that it
> wouldn't make it harder to expand the API later on to allow
> information about intermediate frames.

All frames (that aren't hidden by unittest etc) would be processed the
same way IMO.


Robert Collins <rbtcollins at hp.com>
Distinguished Technologist
HP Converged Cloud

More information about the testing-in-python mailing list