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How to update Data Docs after Validating a Checkpoint

This guide will explain how to use an ActionA Python class with a run method that takes a Validation Result and does something with it to update Data DocsHuman readable documentation generated from Great Expectations metadata detailing Expectations, Validation Results, etc. sites with new Validation ResultsGenerated when data is Validated against an Expectation or Expectation Suite. from running a CheckpointThe primary means for validating data in a production deployment of Great Expectations..

Prerequisites: This how-to guide assumes you have:

Steps​

1. Update your Checkpoint​

A Checkpoint's action_list contains a list of Actions. After the Checkpoint is ValidatedThe act of applying an Expectation Suite to a Batch., these Actions are called in order.

Add an Action to the end of the action_list and name it update_data_docs.

Actions are required to have a single field, action. Inside the action field, a class_name field must be defined, which determines which class will be instantiated to execute this Action.

Add class_name: UpdateDataDocsAction to the Action.

Note:

The StoreValidationResultAction Action must appear before UpdateDataDocsAction Action, since Data Docs are rendered from Validation Results from the StoreA connector to store and retrieve information about metadata in Great Expectations..

 action_list:
   - name: store_validation_result
     action:
       class_name: StoreValidationResultAction
   - name: store_evaluation_params
     action:
       class_name: StoreEvaluationParametersAction
   - name: update_data_docs
     action:
       class_name: UpdateDataDocsAction

2. (Optional) Specify Data Docs sites​

  • By default, the UpdateDataDocsAction updates all Data Docs sites found within your project. To specify which Data Docs sites to update, provide a site_names key to the action config inside your UpdateDataDocsAction. This field accepts a list of Data Docs site names, and when provided, will only update the specified sites.
 action_list:
   - name: store_validation_result
     action:
       class_name: StoreValidationResultAction
   - name: store_evaluation_params
     action:
       class_name: StoreEvaluationParametersAction
   - name: update_data_docs
     action:
       class_name: UpdateDataDocsAction
       site_names:
         - team_site

3. Test your configuration​

Test that your new Action is configured correctly:

Run the Checkpoint from your code or the CLICommand Line Interface and verify that no errors are thrown.

import great_expectations as gx
context = gx.get_context()
checkpoint_name = "your checkpoint name here"
context.run_checkpoint(checkpoint_name=checkpoint_name)
$ great_expectations checkpoint run <your checkpoint name>

Finally, check your Data Docs sites to confirm that a new Validation Result has been added.

Additional notes​

The UpdateDataDocsAction generates an HTML file for the latest Validation Result and updates the index page to link to the new file, and re-renders pages for the Expectation SuiteA collection of verifiable assertions about data. used for that Validation. It does not perform a full rebuild of Data Docs sites. This means that if you wish to render older Validation Results, you should run full Data Docs rebuild (via CLI's great_expectations docs build command or by calling context.build_data_docs()).

Additional resources​