Great Expectations

Great Expectations (GX Core) is an open source data quality framework. Its main building block is the Expectation, an expressive and extensible unit test for data, such as a column whose values must be unique, not null or within a range.

Expectations give data teams a common language to describe data quality. Validation runs can be integrated into a data pipeline or orchestrator, and Actions defined alongside the Expectations can stop bad data from entering a data source or moving downstream and notify the relevant teams. Documentation is generated automatically from validation results. GX Core is used from Python, for example in Jupyter notebooks.

GX Core is open source under the Apache 2.0 licence. It is the engine of the commercial GX data quality platform.