A page carries the date it was last checked against its sources. That date means nothing without a record of what the check found, so every correction is logged here rather than made silently.
22 September 2026
- Corrected: the logging page called structlog’s API on a stdlib logger, which raises
TypeErroronce INFO is enabled. The example now creates a structlog logger, and a library’sNullHandlergoes on its top-level logger only. - Corrected: the Ruff configuration ignored
S101in tests without selecting theSrules, so the ignore did nothing. It now selects them, and leavestarget-versiontorequires-python. - Corrected: the Hypothesis example was named for one property and asserted another. It now asserts the two that define a sort: a permutation of the input, in order.
- Corrected:
TypeAliashas been deprecated since 3.12; the type-checking table now names thetypestatement. - Python versions: added support status and end-of-life dates from the devguide, which version a new project starts on, and the 3.12 to 3.15 changes that were missing. Every PEP cited was checked as Final, with its target version, against the PEP index. The page is re-dated.
- Profiling: added 3.15’s
profiling.sampling, andcProfilebecomingprofiling.tracingunder PEP 799. - Backends: added HTTP clients. httpx has not released since 0.28.1 in December 2024.
- Continuous integration: the example now limits the token to
contents: readand does not persist checkout credentials, and zizmor is listed for auditing workflows. The matrix advice now separates applications from libraries, andsetup-uvcaches by default, so the example no longer asks it to. - Packaging: added a two-stage application image, checked against uv’s Docker guide.
- Softened two claims that had no source: a leaked preprocessing step is “a common” cause of offline-online skew rather than “the most common”, and a lockfile is what makes a figure reproducible rather than “the only thing”.
- Python versions now opens Part II, followed by environments and project layout. No slug changed, so no URL moved. Each example design has its own heading, and so a link.
6 September 2026
- Every tool and PEP in the series now links to its documentation, and a link checker runs over the set. Four canonical URLs had moved: Uvicorn to
uvicorn.dev, Starlette tostarlette.dev, msgspec tomsgspec.dev, and pandas-ta, whose GitHub repository no longer exists, now points at PyPI. - Domains became Part I and practices Part II. Every slug is unchanged, so no URL moved.
- Removed the comparatives that had no source behind them (uv against pip, mypy’s speed, setuptools’ compatibility, asyncpg’s throughput, PyTorch’s dominance) and replaced each with the mechanism that causes it, or with a figure carrying its measurement.
- Concurrency: added the free-threading overhead measurement from PEP 779,
PYTHON_GIL=0and what overriding the GIL re-enablement risks, and the extension constraint that decides whether subinterpreters are usable. - Type checking: the migration section is a procedure rather than a sentence. SQLAlchemy’s mypy plugin has been deprecated since 2.0 and no longer appears as an example of the plugin API.
- Scientific computing: added the array API standard and
array-api-compat;scipy.signal.stft,istftandspectrogramare marked legacy in SciPy’s own reference, withShortTimeFFT(1.12) the current interface; FFTW’s GPL is now stated on the pyFFTW row. - Python 3.11’s speedup is quoted as the release measured it rather than called significant.
- Corrected: LlamaIndex Workflows 1.0 was released in June 2025, not June 2026, and the package has been on 2.x since August 2025.
- Checked and unchanged: pandas 3.0 on 21 January 2026, pyrefly 1.0 in May 2026, PydanticAI V2 on 23 June 2026, the Astral acquisition announced 19 March 2026. The pyrefly row now points at the configuration PyTorch and JAX carry in-tree rather than asserting adoption.
- Python 3.15’s final is scheduled for 1 October 2026 by PEP 790, which the version table now says rather than “Oct 2026”.