Dataframely
Open-source Polars schema validation library by QuantCo that validates Polars DataFrames against dy.Schema classes with column types, nullability, and @dy.rule checks, optionally casting inputs.
Best for Polars teams that want typed schemas with custom rules and casting, without leaving Polars.
Patito
Open-source Polars data modelling library built on Pydantic that validates Polars DataFrames against Pydantic-based models with dtypes, uniqueness, bounds, and custom Polars constraints.
Best for Polars teams that already model data with Pydantic and want those models to validate DataFrames.
Pandera
Open-source DataFrame validation library that validates Polars DataFrames and LazyFrames against schemas, running data-level checks on DataFrames and schema-level checks on LazyFrames.
Best for Python teams that want typed Polars schemas with checks, validated in pipeline code and unit tests.
pointblank
Open-source data validation library by Posit that runs validation plans on Polars tables, with steps that can compute Polars expressions before a check, and reports results as tables.
Best for analysts and engineers who want readable Polars validation reports, starting free in Python.
diffly
Open-source Polars data diff library by QuantCo that compares two Polars DataFrames by primary key, reporting schema differences, rows only on one side, and per-column value changes.
Best for Polars teams that want a fast, readable diff of two DataFrames by primary key.
DataComPy
Open-source DataFrame comparison library from Capital One that compares two Polars DataFrames on join columns and reports row, column, and value differences in a pandas-like report.
Best for migration and refactoring work that needs a row-by-row diff of two Polars datasets with tolerances.
Dataprof
Open-source profiling library with a Rust core that profiles an in-memory Polars DataFrame passed to dp.profile() and exports the results with to_polars().
Best for fast, local profiling of Polars data with quality scores, without a heavy Python stack.
Soda Core
Open-source data contracts engine that registers Polars DataFrames as in-memory DuckDB tables, so Soda data contracts run on them through DuckDB.
Best for teams that want the same YAML data contracts on Polars DataFrames as on their warehouse tables.
Soda Cloud
AI-native data quality platform built on data contracts that registers Polars DataFrames as in-memory DuckDB tables, so Soda data contracts run on them through DuckDB.
Best for teams that want the same YAML data contracts on Polars DataFrames as on their warehouse tables.
Related integrations
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