ExtensionPropertiesApi

Extension Properties API

When working with a DataFrame, the most convenient and reliable way to access its columns — including for operations and retrieving column values in row expressions — is through auto-generated extension properties.

These properties are generated based on the dataframe schema, with their names and types inferred from the names and types of the corresponding columns. This also works for hierarchical DataFrame structures (i.e., column groups and frame columns).

Example

Given the following DataFrame:

You can access columns using extension properties in a type-safe way, avoiding typos and relying on autocompletion. These properties can be used in:

• Columns Selection DSL

• Row Expressions

// Access the "name" column
df.name

// Select the "age" and "height" columns
df.select { age and height }

// Filter rows where "age" > 18 and "name" starts with 'A'
df.filter { age > 18 && name.startsWith("A") }

For more information: See Extension Properties API on the documentation website.