Skip to content

gh-70999: Preserve caller vars in ExtendedInterpolation nested interpolation #155880

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
nikolauspschuetz wants to merge 3 commits into
base: main
Choose a base branch
from
+27 −2
Open

gh-70999: Preserve caller vars in ExtendedInterpolation nested interpolation #155880

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
0ea8e9d
gh-70999: Preserve caller vars in ExtendedInterpolation nested interp…
nikolauspschuetz Aug 16, 2026
2ad6c82
gh-70999: trim verbose test comments per review
nikolauspschuetz Sep 2, 2026
36eb536
Merge remote-tracking branch 'origin/main' into HEAD
nikolauspschuetz Sep 2, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 5 additions & 2 deletions Lib/configparser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -547,9 +547,12 @@ def _interpolate_some(self, parser, option, accum, rest, section, map,
if v is None:
continue
if "$" in v:
if sect == section:
submap = map
else:
submap = dict(parser.items(sect, raw=True))
self._interpolate_some(parser, opt, accum, v, sect,
dict(parser.items(sect, raw=True)),
depth + 1)
submap, depth + 1)
else:
accum.append(v)
else:
Expand Down
19 changes: 19 additions & 0 deletions Lib/test/test_configparser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1361,6 +1361,25 @@ def test_other_errors(self):
with self.assertRaises(ValueError):
cf['interpolation fail']['case6'] = "BLACK $ABBATH"

def test_get_with_vars_nested(self):
# gh-70999: caller-supplied ``vars`` must be honoured at every level
# of a same-section interpolation chain, not just the first.
cf = self.fromstring(textwrap.dedent("""
[section]
a = ${b}
b = ${c}
c = default

[cross]
via = ${section:c}
""").strip())

eq = self.assertEqual
eq(cf.get('section', 'b', vars={'c': 'OVERRIDE'}), 'OVERRIDE')
eq(cf.get('section', 'a', vars={'c': 'OVERRIDE'}), 'OVERRIDE')
eq(cf.get('section', 'a'), 'default')
eq(cf.get('cross', 'via', vars={'c': 'OVERRIDE'}), 'default')
Comment on lines +1377 to +1381

@maurycy maurycy Sep 2, 2026

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.

I think that asserts speak for themselves and the comments here are a bit verbose. The above gh-70999 reference is enough.

@nikolauspschuetz nikolauspschuetz Sep 2, 2026

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.

Trimmed those — the asserts stand on their own now, with just the gh-70999 reference kept. Thanks!



class ConfigParserTestCaseNoValue(ConfigParserTestCase):
allow_no_value = True
Expand Down
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/Library/2026-08-15-12-00-00.gh-issue-70999.NZ96LZ.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Fix :class:`configparser.ExtendedInterpolation` dropping caller-supplied
``vars`` during nested interpolation within a section. Patch by Nikolaus
Schuetz.
Loading