Implementation:Huggingface Datasets Dataset From List

Knowledge Sources	Huggingface Datasets HF Datasets Docs
Domains	Data_Engineering, NLP
Last Updated	2026-02-14 18:00 GMT

Overview

Concrete tool for creating a Dataset from a list of dictionaries provided by the HuggingFace Datasets library.

Description

Dataset.from_list is a class method that converts a list of dictionaries into a Dataset. Each dictionary in the list represents one row, with keys as column names and values as cell values. The keys of the first dictionary determine the dataset columns. Internally, the list is transposed into a columnar dictionary and then delegated to Dataset.from_dict. The resulting dataset lives in memory without an associated cache directory.

Usage

Use Dataset.from_list when your data is organized as a list of records (row-oriented dictionaries), which is common when reading JSON arrays, collecting API responses, or building datasets from query results.

Code Reference

Source Location

• Repository: datasets
• File: src/datasets/arrow_dataset.py
• Lines: 1037-1067

Signature

@classmethod
def from_list(
    cls,
    mapping: list[dict],
    features: Optional[Features] = None,
    info: Optional[DatasetInfo] = None,
    split: Optional[NamedSplit] = None,
) -> "Dataset":

Import

from datasets import Dataset

I/O Contract

Inputs

Name	Type	Required	Description
mapping	list[dict]	Yes	A list of dictionaries mapping column names to row values.
features	Features	No	Explicit dataset features schema.
info	DatasetInfo	No	Dataset metadata (description, citation, etc.).
split	NamedSplit	No	Name of the dataset split.

Outputs

Name	Type	Description
return	Dataset	A new in-memory Dataset built from the list of dictionaries.

Usage Examples

Basic Usage

from datasets import Dataset

data = [
    {"text": "Hello world", "label": 1},
    {"text": "Goodbye world", "label": 0},
]
ds = Dataset.from_list(data)
print(ds)
# Dataset({
#     features: ['text', 'label'],
#     num_rows: 2
# })

Related Pages

Implements Principle

• Principle:Huggingface_Datasets_Dataset_From_List_Construction