DuckPlus 1.0

DuckPlus 1.0 introduces a cohesive workflow for managing DuckDB relations with immutable semantics, typed expression helpers, and curated IO adapters. The API surface adheres to the open/closed principle: new capabilities are layered on top of the existing connection, relation, and typed expression primitives without forcing breaking changes. The reference documentation is divided into guides that mirror the main developer journeys—from opening a managed connection to shipping data products. Each chapter now calls out guard-rails, integration tips, and direct links to the underlying implementation so you can trace behaviour with confidence.

Tip

All code snippets in the 1.0 guides run against the duckplus package published on PyPI. They assume Python 3.11+ and DuckDB 0.10+; if you are pinned to an older runtime, consult the ../typed_api appendix for migration notes and breaking-change callouts.

Release highlights

• Immutable-first relations keep transformations predictable while exposing convenient exporters for Arrow, Pandas, and Polars.

• Typed expressions provide static guarantees around column usage and integrate directly with the Select builder.

• IO adapters and extension helpers surface DuckDB’s ecosystem in a Pythonic way, offering first-run installation guidance and actionable errors.

The sections below walk through the features in increasing depth. Jump straight to the area you care about or read sequentially to build a mental model of the entire stack.

Start here

• Getting started
  • Verifying your environment
  • Opening a connection
  • Working with immutable relations
  • Typed expression DSL
  • Next steps
  • Documentation navigation
• Connection management with DuckCon
  • Lifecycle management
  • Extension loading
  • Connection configuration
  • Relationship with relations
  • Registering custom helpers
  • Testing patterns
• Immutable relation helpers
  • Constructing relations
  • Column management
  • Projection builder
  • Aggregation and window functions
  • Filtering and joins
  • Schema utilities
  • Introspection and diagnostics
  • Exporting data
• Typed expression API
  • Creating typed expressions
  • Arithmetic and comparison helpers
  • Aggregation helpers
  • Window functions
  • Conditional expressions and aliases
  • Scalar helpers
  • Select builder
  • Debugging typed expressions
• File and table readers
  • CSV reader
  • Parquet reader
  • JSON, Arrow, and database connectors
  • Composing with custom helpers
• File append helpers
  • CSV appends
  • Parquet appends
  • Table utilities
• Community extension coverage
  • Nano-ODBC
  • Excel
  • Bundled extensions
  • Roadmap
• Schema management
  • Inspecting schemas
  • Diffing relations
  • Exporters
  • Table utilities
• Practitioner demos
  • Language Server Demonstration
  • Raspberry Pi Typed Expression Demo
  • Sales analytics pipeline demo
  • Language server walkthrough
  • Pi approximation notebook
  • Schema diff quickstart
  • Sales analytics pipeline
  • Contributing demos

If you are upgrading from an earlier preview, the Getting started chapter highlights the stable import paths, while the deep-dive guides explain how each helper composes with DuckDB. For a tour of real-world usage, Practitioner demos showcases language server walkthroughs, notebooks, and the deterministic sales_pipeline project that powers many of the examples. The reference/index reference documents every public class, method, and function in the 1.0 API surface so static tooling and application developers can reason about DuckPlus without inspecting the source code.