Retain Action

The retain action allows you to keep only the keys or fields that you specify, while discarding all others. It takes a list of keys as an argument, and retains only those keys in the item being processed.

Here’s an example of how you might use the retain action in a YAML file:

actions:
  retain_important_fields:
    action: retain
    keys: [NAME, AGE, GENDER]

This retain action will keep only the keys NAME, AGE, and GENDER in the item being processed, discarding all other keys.

Here’s an example of how the retain action might be used in a more complete processing pipeline:

actions:
  retain_important_fields:
    action: retain
    keys: [NAME, AGE, GENDER]
  rename_fields:
    action: rename
    mapping:
			OLD_FIELD_NAME: NEW_FIELD_NAME
			OLD_FIELD_NAME_2: NEW_FIELD_NAME_

In this example, the retain action is used first to keep only the keys NAME, AGE, and GENDER in the item being processed. Then, the convert_fields action is used to convert the data type of the AGE and GENDER fields to INTEGER and STRING, respectively. Finally, the add_default_values action is used to add default values for the AGE and GENDER fields, in case they are not present in the item.

rename_fields: action: rename mapping: OLD_FIELD_NAME: NEW_FIELD_NAME OLD_FIELD_NAME_2: NEW_FIELD_NAME_