FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

gh-93343: Expand warning filter examples by daniel-shimon · Pull Request #106618 · python/cpython · GitHub

  1. python
  2. cpython

Repository navigation

gh-93343: Expand warning filter examples #106618

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
daniel-shimon wants to merge 5 commits into
base: main
Choose a base branch
Could not load branches
Branch not found: {{ refName }}

Are you sure you want to change the base?

Some commits from the old base branch may be removed from the timeline, and old review comments may become outdated.
from
Conversation 31 Commits 5 Checks 42 Files changed
Open

gh-93343: Expand warning filter examples #106618

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
e43adf8
gh-93343: Expand warning filter examples
daniel-shimon Jul 12, 2023
f3684a6
gh-93343: Add warning filters tests
daniel-shimon Jul 12, 2023
f16ae2d
Clarify escaped dots in regexes
daniel-shimon May 6, 2025
e6251be
Merge branch 'main' into gh-93343-extra-warning-examples
daniel-shimon May 6, 2025
53a8662
Fix CR Comments
daniel-shimon Nov 23, 2025
File filter

Filter by extension

Filter by extension .py  (1) .rst  (2) All 2 file types selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
36 changes: 36 additions & 0 deletions Doc/library/warnings.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -229,6 +229,42 @@ Some examples::
ignore,default:::mymodule # Only report warnings triggered by "mymodule"
error:::mymodule # Convert warnings to errors in "mymodule"

.. _warning-filter-examples:

Warning Filter Examples
~~~~~~~~~~~~~~~~~~~~~~~

Here are some complex examples for filtering warnings.

Note that :func:`filterwarnings` filters have subtle differences
from :option:`-W` and :envvar:`PYTHONWARNINGS` regarding the *message* and *module*
parts of the filter (as described in :ref:`warning-filter`).
Mainly, 'message' and 'module' are regular expressions in the former,
but literal strings in the latter two.

::

filterwarnings("ignore", message=".*generic", module=r"yourmodule\.submodule")

ezio-melotti Jul 11, 2023

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality
Suggested change
filterwarnings("ignore", message=".*generic", module=r"yourmodule\.submodule")
filterwarnings("ignore", message="\.*generic", module="yourmodule\.submodule")

Shouldn't this be escaped as well? The r here is not necessary, and its usage should be consistent between the two args (assuming they are both regexes).

daniel-shimon Jul 12, 2023

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

No since the first arg wants to capture strings that contain 'generic' so that the '.' catches everything, while the first arg want to capture 'yourmodule.submodule' specifically, meaning that the '.' actually captures dot and should be escaped

erlend-aasland Jul 12, 2023

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Well, it sounds to me you should put that explanation into the docs, @daniel-shimon; if it is unclear for a reviewer, it is not going to be clear for the average docs reader ;)
# Ignore warnings in "yourmodule.submodule" which contain "generic".
# Note that the '.' in 'message' marks any character and in 'module' it is escaped,
# in order to match a literal dot character.

filterwarnings("ignore", message="generic", module=r"yourmodule\.submodule")
# Ignore warnings in "yourmodule.submodule" which START with "generic".

filterwarnings("ignore", module="yourmodule.*")
Comment thread
daniel-shimon marked this conversation as resolved.
# Ignore all warnings in "yourmodule" and its submodules.
# Note that the '.' in 'module' marks any character so is not escaped.

-W "ignore:generic::yourmodule.submodule:"
# Ignore warnings in "yourmodule.submodule" which START with "generic"
# (but not those containing it).
# Also note that the '.' in the module part does not need to be escaped
# since it is not a regular expression.

-W "ignore:::yourmodule:"
# Ignore all warnings in "yourmodule", but NOT in its submodules.


.. _default-warning-filter:

Expand Down
24 changes: 24 additions & 0 deletions Lib/test/test_warnings/__init__.py
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -318,6 +318,18 @@ def test_message_matching(self):
self.module.warn("something completely different")
self.assertEqual(w, [])

def test_message_matching_regex(self):
with original_warnings.catch_warnings(record=True,
module=self.module) as w:
self.module.simplefilter("ignore", UserWarning)
self.module.filterwarnings("error", ".*match", UserWarning)
self.assertRaises(UserWarning, self.module.warn, "match")
self.assertRaises(UserWarning, self.module.warn, "match prefix")
self.assertRaises(UserWarning, self.module.warn, "suffix match")
self.assertEqual(w, [])
self.module.warn("not a m4tch")
self.assertEqual(w, [])

def test_mutate_filter_list(self):
class X:
def match(self, a):
Expand Down Expand Up @@ -1352,6 +1364,18 @@ def test_single_warning(self):
PYTHONDEVMODE="")
self.assertEqual(stdout, b"['ignore::DeprecationWarning']")

def test_string_literals(self):
# Ensure message/module are treated as string literals
_, stdout, stderr = assert_python_ok("-c",
"import sys, warnings; "
"sys.stdout.write(warnings.filters[0][1].pattern); "
"sys.stderr.write(warnings.filters[0][3].pattern)",
PYTHONWARNINGS="ignore:.generic::yourmodule.submodule",
PYTHONDEVMODE="")
self.assertEqual(stdout, rb"\.generic")
# '\Z' is added to the module name, so check start of pattern:
self.assertTrue(stderr.startswith(rb"yourmodule\.submodule"))

def test_comma_separated_warnings(self):
rc, stdout, stderr = assert_python_ok("-c",
"import sys; sys.stdout.write(str(sys.warnoptions))",
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Documentation/2023-07-11-08-46-13.gh-issue-93343.fw_eyw.rst
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Add examples of warning filters and the difference between programmatic and
environmental filters.
Loading
Back | FazBrowse Home | New Git URL