Skip to main content
The first output column will contain the items in the first position of the input lists, the second column items in the second position etc.

​
Usage

The following examples show how the step can be used in a recipe.

Examples

Extract the first 3 items from a list column into separate columns
unpack_list(ds.coordinates, {"n_items": 3}) => (ds.coord_parts)

​
Inputs & Outputs

The following are the inputs expected by the step and the outputs it produces. These are generally columns (ds.first_name), datasets (ds or ds[["first_name", "last_name"]]) or models (referenced by name e.g. "churn-clf").
​
lists
column[list]
required
An input column containing lists to unpack.
​
list_items
dataset
required
The output dataset containing list elements in individual columns.

​
Configuration

The following parameters can be used to configure the behaviour of the step by including them in a json object as the last “input” to the step, i.e. step(..., {"param": "value", ...}) -> (output).

Parameters

​
start
integer
default:"0"
List index of first element to extract.Values must be in the following range:
0 ≤ start < inf
​
n_items
integer
default:"1"
Total number of consecutive items to extract from lists.Values must be in the following range:
1 ≤ n_items < inf
​
prefix
[string, null]
Prefix for names of generated columns. By default, will use the output dataset’s name concatenated with “_0”, “_1” etc. for the first extracted column, the second column etc. respectively. I.e. you name the output dataset of this step list_items, then its columns will be named “list_items_0”, “list_items_1” etc. If a prefix is provided, this will be used instead of the output dataset’s name.
​
column_names
array[string]
A list of names for the columns in the output dataset. Will be used only if the number of names passed matches the n_items parameter.
​
Item
string
The name of a single column in the ouput.