port lazy_loader perf and native PEP810 + add python3.15 support

[benedikt-bartscher]

scientific-python/lazy-loader#172
scientific-python/lazy-loader#173

[codspeed-hq]

Merging this PR will improve performance by 5.22%

⚡ 4 improved benchmarks
✅ 28 untouched benchmarks
⏩ 8 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	test_evaluate_page[_complicated_page]	26.7 ms	25.2 ms	+6%
⚡	Simulation	test_evaluate_page_with_hooks[_complicated_page]	26.9 ms	25.4 ms	+5.9%
⚡	Simulation	test_evaluate_page[_stateful_page]	4.6 ms	4.4 ms	+4.58%
⚡	Simulation	test_evaluate_page_with_hooks[_stateful_page]	4.8 ms	4.6 ms	+4.4%

Tip

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_{Comparing benedikt-bartscher:use-lazy-loader-branch (bd08a51) with main (dd96aea)}

Footnotes

1. 8 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[greptile-apps]

Greptile Summary

The PR adds Python 3.15 support and introduces native PEP 810 lazy imports while optimizing classic lazy attribute resolution.

• Adds Python 3.15 to unit and integration CI matrices.
• Introduces a Python 3.15-compatible dataclass missing-value type and TypedDict sentinel handling.
• Uses native lazy imports on Python 3.15 and caches resolved attributes on older runtimes.
• Adjusts development dependencies and test expectations for current Python 3.15 package compatibility.

Confidence Score: 5/5

The PR appears safe to merge because no blocking failure remains in the eligible review scope.

No blocking failure remains.

Important Files Changed

Filename	Overview
packages/reflex-base/src/reflex_base/utils/lazy_loader.py	Adds native PEP 810 bindings and package-level caching for resolved lazy attributes.
packages/reflex-base/src/reflex_base/utils/compat.py	Provides a public compatibility alias for the dataclass missing-value sentinel type.
packages/reflex-base/src/reflex_base/utils/types.py	Normalizes Python and typing-extensions NoExtraItems sentinels during TypedDict validation.
pyproject.toml	Selects pure-Python psycopg on Python 3.15 while retaining the binary extra on older versions.
uv.lock	Regenerates Python-version resolution partitions and psycopg markers for Python 3.15.
.github/workflows/unit_tests.yml	Extends Linux, Windows, and macOS unit-test matrices to Python 3.15.

_{Reviews (12): Last reviewed commit: "Merge branch 'main' into use-lazy-loader..." | Re-trigger Greptile}

[cubic-dev-ai]

All reported issues were addressed across 17 files

<sub>Reply with feedback, questions, or to request a fix.

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