Package list

Packages for data validation

Python packages for validating, parsing, and type-checking data, from runtime type guards to schema-based validators and DataFrame quality tools.

	Comment
pydantic	The most widely used data validation library, using Python type hints to define and validate data models.	27.8M	18	—
marshmallow	A library for object serialization, deserialization, and validation via declarative schemas.	3.7M	11	7,409
msgspec	High-performance serialization and validation library using Python type annotations, with JSON and MessagePack support.	1.1M	4	3,157
cattrs	Structuring and unstructuring of attrs and dataclass objects, with composable validation hooks.	2.0M	3	591
jsonschema	Reference implementation of the JSON Schema specification for validating JSON documents.	14.8M	1	1,323
cerberus	Lightweight and extensible schema validation for Python dictionaries.	210K	1	2,635
voluptuous	Schema validation library focused on validating data coming into Python from external sources.	205K	1	2,030
pandera	Statistical data validation for pandas, Polars, and other DataFrame libraries, with type annotations support.	305K	18	1,450
great-expectations	Data quality framework for defining, documenting, and validating expectations on large datasets in pipelines.	840K	35	11,184
typeguard	Runtime type checking for Python functions and variables, enforcing type annotations at execution time.	2.0M	4	1,719
beartype	Fast runtime type checker using O(1) constant-time type checks with no overhead at scale.	2.1M	10	3,128

docling-coreA python library to define and validate data types in Docling.
jsonschema-rsA high-performance JSON Schema validator for Python
validatorsPython Data Validation for Humans™
schemaSimple data validation library
checkdigitA check digit library for data validation
typepytypepy is a Python library for variable type checker/validator/converter at a run time.
tyAn extremely fast Python type checker, written in Rust.
hypothesisThe property-based testing library for Python
pydantic-coreCore functionality for Pydantic validation and serialization
dataclass-wizardA wizard-like JSON serialization library for Python dataclasses

docling-coreA python library to define and validate data types in Docling.
jsonschema-rsA high-performance JSON Schema validator for Python
validatorsPython Data Validation for Humans™
schemaSimple data validation library
checkdigitA check digit library for data validation
typepytypepy is a Python library for variable type checker/validator/converter at a run time.
tyAn extremely fast Python type checker, written in Rust.
hypothesisThe property-based testing library for Python
pydantic-coreCore functionality for Pydantic validation and serialization
dataclass-wizardA wizard-like JSON serialization library for Python dataclasses

	Comment
pydantic	The most widely used data validation library, using Python type hints to define and validate data models.	27.8M	18	—
marshmallow	A library for object serialization, deserialization, and validation via declarative schemas.	3.7M	11	7,409
msgspec	High-performance serialization and validation library using Python type annotations, with JSON and MessagePack support.	1.1M	4	3,157
cattrs	Structuring and unstructuring of attrs and dataclass objects, with composable validation hooks.	2.0M	3	591
jsonschema	Reference implementation of the JSON Schema specification for validating JSON documents.	14.8M	1	1,323
cerberus	Lightweight and extensible schema validation for Python dictionaries.	210K	1	2,635
voluptuous	Schema validation library focused on validating data coming into Python from external sources.	205K	1	2,030
pandera	Statistical data validation for pandas, Polars, and other DataFrame libraries, with type annotations support.	305K	18	1,450
great-expectations	Data quality framework for defining, documenting, and validating expectations on large datasets in pipelines.	840K	35	11,184
typeguard	Runtime type checking for Python functions and variables, enforcing type annotations at execution time.	2.0M	4	1,719
beartype	Fast runtime type checker using O(1) constant-time type checks with no overhead at scale.	2.1M	10	3,128