Flatten List
Uncontrolled node
Overview
The Flatten List node is used to merge nested lists into a single list, removing layers of list nesting based on the specified depth.
This is especially useful when working with structured data like lists of lists—for example, output from a document reader, batch input, or grouped responses—and you want to simplify the structure for further processing.
Inputs
| Input | Type | Description | Default |
|---|---|---|---|
| List | List | A list of items, possibly containing other lists (nested lists) | - |
Outputs
| Output | Type | Description |
|---|---|---|
| Output | List | A flattened list with nesting reduced to the specified depth |
Panel Controls
The Depth field in the right-side panel controls how deeply the list is flattened.
- A depth of
1will flatten only the top-level of nesting. - A higher number will recursively flatten deeper layers.
- If not specified, the default is 1.
Example: One-Level Flatten
If your list is:
[["a", "b"], ["c", "d"]]
and the depth is:
1
The output will be:
a,b,c,d
Tip
Use a higher depth when your data has multiple levels of nested lists. For most document or CSV outputs, a depth of 1 is usually enough.