Levels of Maturity

Features and code within Great Expectations are separated into three levels of maturity: Experimental, Beta, and Production.

•   Experimental: Try, but do not rely
•   Beta: Ready for early adopters
•   Production: Ready for general use

Being explicit about these levels allows us to enable experimentation, without creating unnecessary thrash when features and APIs evolve. It also helps streamline development, by giving contributors a clear, incremental path to create and improve the Great Expectations code base.

For users of Great Expectations, our goal is to enable informed decisions about when to adopt which features.

For contributors to Great Expectations, our goal is to channel creativity by always making the next step as clear as possible.

This grid provides guidelines for how the maintainers of Great Expectations evaluate levels of maturity. Maintainers will always exercise some discretion in determining when any given feature is ready to graduate to the next level. If you have ideas or suggestions for leveling up a specific feature, please raise them in Github issues, and we’ll work with you to get there.

Criteria	Experimental Try, but do not rely	Beta Ready for early adopters	Production Ready for general use
API stability	Unstable*	Mostly Stable	Stable
Implementation completeness	Minimal	Partial	Complete
Unit test coverage	Minimal	Partial	Complete
Integration/Infrastructure test coverage	Minimal	Partial	Complete
Documentation completeness	Minimal	Partial	Complete
Bug risk	High	Moderate	Low

note

Experimental classes log warning-level messages when initialized:

Warning: great_expectations.some_module.SomeClass is experimental. Methods, APIs, and core behavior may change in the future.

Contributing Expectations

The workflow detailed in our initial guides on Creating Custom Expectations will leave you with an Expectation ready for contribution at an Experimental level. The checklist generated by the print_diagnostic_checklist() method will help you walk through the requirements for Beta & Production levels of contribution; the first four checks are required for Experimental acceptance, the following three are additionally required for Beta acceptance, and the final three (a full checklist!) are required for Production acceptance. Supplemental guides are available to help you satisfy each of these requirements.

Criteria	Experimental Try, but do not rely	Beta Ready for early adopters	Production Ready for general use
Has a library_metadata object	✔	✔	✔
Has a docstring, including a one-line short description	✔	✔	✔
Has at least one positive and negative example case, and all test cases pass	✔	✔	✔
Has core logic and passes tests on at least one Execution Engine	✔	✔	✔
Has basic input validation and type checking	―	✔	✔
Has both Statement Renderers: prescriptive and diagnostic	―	✔	✔
Has core logic that passes tests for all applicable Execution Engines	―	✔	✔
Passes all linting checks	―	―	✔
Has a robust suite of tests, as determined by a code owner	―	―	✔
Has passed a manual review by a code owner for code standards and style guides	―	―	✔