An opinionated reference to the state of the art of Python 2026, including language features and the ecosystem with examples.
TLDRQuick reference for state-of-the-art defaults in Python projects.Part I: Domains
Backends, databases and APIsFrameworks, HTTP servers and clients, data access, queues, and two example service designs.Data engineeringColumnar formats, local analytics, orchestration, and lakehouse tables.Data scienceArrays, dataframes, reproducible analysis, and sensor time series.Scientific computing and signal processingNumerical computing, instruments, SDR, RF, and parameter studies.Machine learningTraining and serving, with tabular and vision examples.Markets and financial dataMarket data, point-in-time storage, and backtesting.LLMs, agents and retrievalProvider clients, agent workflows, retrieval, and structured extraction.Part II: Practices
Environments and dependenciesuv, project interpreters, and dependency management, with alternatives.Project configuration and layoutProject metadata, dependency groups, src layout, and lockfiles.Linting and formattingRuff for linting and formatting, with an explicit rule set.Type checkingType checkers, useful annotations, and incremental migration.Validation and data modelsBoundary validation, internal data models, and startup configuration checks.ErrorsException groups and package-level error conventions.LoggingApplication-level configuration, structured fields, and library logging boundaries.ConcurrencyConcurrency models, their use cases, and free-threading status.TestingFixtures, parametrization, property-based tests, and integration boundaries.Command-line interfaces and single-file scriptsPython CLIs and inline metadata for standalone scripts.DocumentationDocumentation generators and what annotations leave unspecified.Continuous integrationA CI pipeline, and the checks and hardening it most often lacks.Packaging and distributionBuild backends, distributions, an application image, and a published library layout.Maintenance
ChangelogThe changes recorded in each review, with dates.