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Title: Add "ignore_modules" option to TracebackException.format()
Type: enhancement Stage: patch review
Components: Library (Lib) Versions: Python 3.10
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: brett.cannon, iritkatriel, ncoghlan, pablogsal, pitrou, rbcollins
Priority: normal Keywords: patch

Created on 2017-08-29 07:45 by ncoghlan, last changed 2022-04-11 14:58 by admin.

Pull Requests
URL Status Linked Edit
PR 26772 closed iritkatriel, 2021-06-17 16:11
PR 28067 merged iritkatriel, 2021-08-30 13:49
Messages (10)
msg300974 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-08-29 07:45
This is a proposed traceback module enhancement deriving from the "python -m" traceback verbosity discussion in issue 16217.

Specifically, I'm thinking a good way of cleaning up those tracebacks would be to use `TracebackException.format()` to get the formatted exception output, but designate particular modules to be *skipped* during the iteration (specifically `runpy`, `_frozen_importlib`, `importlib`).

I'm filing this as a separate issue so the discussion of the public API for the capability in the traceback module can be separated from the discussion of applying that API in runpy.
msg301791 - (view) Author: Antoine Pitrou (pitrou) * (Python committer) Date: 2017-09-09 20:32
I think a more general facility to strip unwanted frames from traceback objects would be useful for more people (including importlib, I think).  i.e. actually mutate the traceback object, not remove the unwanted frames when printing (since it only works if you're the one doing the printing).

(note mutating a traceback object is very easy in C, it's just not possible in pure Python, except perhaps with nasty ctypes hacks)

Also, the `ignore_modules` would be more powerful as a generic `filter` callback, I think.
msg302892 - (view) Author: Dmitry Kazakov (vaultah) * Date: 2017-09-24 22:51
Yes, a public built-in facility to modify a traceback would certainly be useful, although there should be a standard way to "hide" unwanted frames without mutating the traceback, too, and the traceback module seems a perfect place to add it.

I have no objections to the `filter` argument, though filtering out frames based on modules to me feels by far more common a task than anything else `filter` would be capable of.

I can update the PR if there's a consensus that `filter` is favored over `ignore_modules`.
msg304921 - (view) Author: Dmitry Kazakov (vaultah) * Date: 2017-10-24 15:54
Ping. (this issue needs a decision on ignore_modules vs filter callback, and/or patch review)
msg305996 - (view) Author: Dmitry Kazakov (vaultah) * Date: 2017-11-09 23:07
I only recently realized that trace.Trace accepts two similar arguments, namely ignoremods and ignoredirs. Should we try to make the API and implementation of the functionality proposed here conform to that of trace.Trace's ignoremods? Would Python-Ideas be a more appropriate place to discuss this?
msg306762 - (view) Author: Pablo Galindo Salgado (pablogsal) * (Python committer) Date: 2017-11-22 23:48
I have prepared a patch (attached) with a possible implementation of the C function that can filter traceback objects modifying the traceback chain. I can make a PR if the patch looks good enough to start iterating over it. In case an alternative implementation is needed I am more than happy to prepare another patch/PR.
msg328137 - (view) Author: Dmitry Kazakov (vaultah) * Date: 2018-10-20 14:02
I asked for some input on this issue in January ( Since then an important PR was merged (, however it mutates the traceback object. Should there be a way to hide frames while keeping the original traceback object intact? If not, this issue should probably be closed. Otherwise I would appreciate a review of the PR.
msg334399 - (view) Author: Dmitry Kazakov (vaultah) * Date: 2019-01-26 20:58
It would seem no one is actually interested in this proposed enhancement. I'm closing my PR, since I'm not interested in resolving the file conflict. I'll probably submit a traceback-mutating patch to the issue 16217. This issue can be closed.
msg382694 - (view) Author: Irit Katriel (iritkatriel) * (Python committer) Date: 2020-12-07 23:01
In issue42247 the unit test framework uses limit as a hack to remove its own frame, and then the traceback module applies the limit to the chained exception as well.

If the filter suggested here existed, unit test could use that instead of limit.
msg400777 - (view) Author: Irit Katriel (iritkatriel) * (Python committer) Date: 2021-08-31 20:42
New changeset 863154c9292e70c5a8a1a3f22ef4ee42e2304281 by Irit Katriel in branch 'main':
bpo-31299: make it possible to filter out frames from tracebacks (GH-28067)
Date User Action Args
2022-04-11 14:58:51adminsetgithub: 75480
2021-08-31 20:42:18iritkatrielsetmessages: + msg400777
2021-08-30 13:49:41iritkatrielsetpull_requests: + pull_request26511
2021-06-17 16:11:46iritkatrielsetpull_requests: + pull_request25358
2020-12-07 23:02:15iritkatrielsetversions: + Python 3.10, - Python 3.7
2020-12-07 23:01:36iritkatrielsetnosy: + iritkatriel
messages: + msg382694
2019-01-26 21:00:08vaultahsetnosy: - vaultah
2019-01-26 20:59:35vaultahsetpull_requests: - pull_request11522
2019-01-26 20:59:04vaultahsetpull_requests: + pull_request11522
2019-01-26 20:58:53vaultahsetpull_requests: - pull_request5065
2019-01-26 20:58:17vaultahsetnosy: brett.cannon, ncoghlan, pitrou, rbcollins, vaultah, pablogsal
messages: + msg334399
2018-10-20 14:10:00pablogsalsetfiles: - traceback_filter.patch
2018-10-20 14:02:22vaultahsetmessages: + msg328137
2018-01-16 23:48:56vaultahsetstage: needs patch -> patch review
pull_requests: + pull_request5065
2017-11-22 23:48:29pablogsalsetfiles: + traceback_filter.patch

nosy: + pablogsal
messages: + msg306762

keywords: + patch
2017-11-22 00:29:20vaultahsetpull_requests: - pull_request3274
2017-11-09 23:07:56vaultahsetmessages: + msg305996
2017-10-24 15:54:13vaultahsetmessages: + msg304921
2017-09-24 22:51:35vaultahsetmessages: + msg302892
2017-09-09 20:32:57pitrousetnosy: + pitrou, brett.cannon
messages: + msg301791
2017-08-29 09:18:20vaultahsetpull_requests: + pull_request3274
2017-08-29 07:46:41ncoghlanlinkissue16217 dependencies
2017-08-29 07:45:45ncoghlancreate