From the course: Data Quality Testing with Great Expectations
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Defining Expectations - Great Expectations Tutorial
From the course: Data Quality Testing with Great Expectations
Defining Expectations
Now that we're connected to the data in our Postgres database, we can finally get started and write some expectations. In Gx, an expectation is a statement that expresses what we expect from our data that we can then verify. It's basically a data assertion. For example, we can say that we expect every pickup time field in the taxi data to be non-null because we need to know the exact date and time of the ride. Or we may assert that every taxi ride needs to have at least one passenger, that the pickup time is before the drop-off time, and that the total fare needs to be the sum of the base fare and all additional fees and tips. GX comes with many expectation types already built in, which helps us get started quickly. A good way to start writing expectations is to check out the expectation gallery to see if the expectation that we want to write already exists. Let's take a look at the expectation gallery on the GX website. Let's try and find a built-in expectation that asserts that all…
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