An Expectation is a declarative statement that a computer can evaluate, and that is semantically meaningful to humans, like expect_column_values_to_be_unique or expect_column_mean_to_be_between. Expectations are implemented as classes that provide a rich interface to the rest of the library to support validation, profiling, and translation. Some Expectations are implemented in the core library. Many others are contributed by the community of data practitioners that bring their domain knowledge and share it as Expectations
If you don't see an Expectation you are looking for you can make it yourself and become a contributor to the project!
Can't find the Expectation you need?Learn how to create an Expectation here