build(deps-dev): bump black to 26.3.1 and apply formatting

[yuneng-berri]

What

Bumps the pinned black dev dependency from 24.10.0 to 26.3.1 and applies the resulting formatting.

• pyproject.toml: black==24.10.0 → black==26.3.1
• uv.lock: re-locked (black updated, pytokens added as a new transitive dependency)
• 89 files under litellm/ reformatted by Black 26.3.1

The formatting changes are limited to two style updates introduced across the 2025/2026 Black style years: collapsing a redundant blank line after a module-level import block, and adding a magic trailing comma to multi-line single-argument signatures. Black re-parses and AST-compares its output by default, so these changes are semantically equivalent.

The reformat is scoped to litellm/ excluding litellm/enterprise/, matching what CI's black --check enforces.

Test plan

• uv lock --check passes (lock in sync with pyproject.toml)
• black --check --exclude '/enterprise/' . (run from litellm/, the exact CI invocation) reports all 1834 files clean

No runtime code changed — this is a tooling/formatting-only change, so no new tests apply.

[greptile-apps]

Greptile Summary

This PR bumps the black dev dependency from 24.10.0 to 26.3.1 and applies the resulting reformatting to 89 files under litellm/ (excluding enterprise/). All code changes are purely stylistic — no runtime logic was touched.

• pyproject.toml / uv.lock: black version updated; pytokens 0.4.1 added as a new transitive dependency of black 26.3.1; uv.lock's exclude-newer field updated from its placeholder value to the actual generation timestamp.
• 89 litellm/ source files: Two mechanical style changes applied by Black — blank lines after import blocks collapsed, and magic trailing commas added to multi-line single-argument signatures. String assignments wrapped in redundant parentheses were also inlined. Black's AST-comparison pass guarantees semantic equivalence for all transformations.

Confidence Score: 5/5

All 89 source-file changes are Black-verified, AST-equivalent reformatting with no logic alterations; safe to merge.

Every changed line in litellm/ is a whitespace or parenthesis adjustment produced by Black's formatter, which compares ASTs before and after to guarantee no behavioral change. The only new artifact is pytokens 0.4.1, a well-scoped transitive dependency introduced by Black itself. The one noted issue (duplicate # noqa) is a cosmetic artifact of line collapsing.

No files require special attention; uv.lock and pyproject.toml are the only non-source changes and both reflect the expected version bump.

Important Files Changed

Filename	Overview
pyproject.toml	Bumps black dev dependency from 24.10.0 to 26.3.1; no other changes.
uv.lock	Re-locked for black 26.3.1; adds pytokens 0.4.1 as a new transitive dependency; exclude-newer updated from placeholder to actual generation timestamp.
litellm/proxy/proxy_cli.py	Pure formatting: string concatenation inlined; duplicate # noqa comment introduced by black on the collapsed closing line.
litellm/litellm_core_utils/litellm_logging.py	Pure formatting: parentheses removed from single-string assignments; semantically identical.
litellm/proxy/utils.py	Pure formatting: f-string arguments inlined with function calls; semantically identical.
litellm/router.py	Pure formatting: trailing comma added to multi-line function signature; no logic change.

_{Reviews (1): Last reviewed commit: "style: apply black 26.3.1 formatting" | Re-trigger Greptile}

[greptile-apps]

Black collapsed both # noqa annotations from the original opening and closing parentheses onto the single closing line, producing a duplicate # noqa. This is harmless but untidy.

Suggested change

	""") # noqa # noqa
	""") # noqa

[codecov]

Codecov Report

❌ Patch coverage is 40.00000% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
litellm/litellm_core_utils/litellm_logging.py	0.00%	2 Missing ⚠️
litellm/proxy/proxy_cli.py	50.00%	1 Missing ⚠️
litellm/proxy/proxy_server.py	0.00%	1 Missing ⚠️
...proxy/spend_tracking/spend_management_endpoints.py	0.00%	1 Missing ⚠️
litellm/proxy/utils.py	50.00%	1 Missing ⚠️

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