openml

library0.15.1pypypi✓ verified 83d ago

OpenML Python API for downloading, uploading, and managing datasets, tasks, runs, and flows on OpenML.org. Current version 0.15.1, requires Python >=3.8. Released under BSD license. Active development with periodic releases.

data ai-ml

pip install openml

github ↗package ↗homepage ↗docs ↗

INSTALL

IMPORT

SIG · OPENML

openml

datapythonv0.15.1

Install

18.8s avg

Import

5602ms

Disk

523MB

Pass rate

5/ 10

Env Coverage5 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.15.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

build_error

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 18.8s · import 5.602s · 511MB

523MB installed

● package 523MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

openml

✓ import openml

✗ from openml import *

Wildcard imports discouraged; use explicit submodules like openml.datasets.

openml.datasets

✓ from openml.datasets import get_dataset

✗ from openml.datasets import list_datasets

list_datasets is deprecated, use openml.datasets.list_datasets() or openml.datasets.get_dataset_list().

openml.tasks

✓ from openml.tasks import get_task

✗ import openml.tasks as tasks

That works, but ensure using correct function names.

Setup OpenML, list datasets, download and inspect the Iris dataset.

import openml openml.config.apikey = openml.config.get_api_key() # uses ~/.openml/config or environment # List datasets datasets = openml.datasets.list_datasets() print(f"Number of datasets: {len(datasets)}") # Download a dataset (iris) dataset = openml.datasets.get_dataset(61) X, y, categorical_names, attribute_names = dataset.get_data(target=dataset.default_target_attribute) print(X.head())

Debug

Known issues

breakingIn version 0.14, the `get_dataset` method changed from returning a tuple to returning a `OpenMLDataset` object. Calling `get_data()` now returns four values (X, y, categorical_indicator, attribute_names) instead of previously different structure.

fix

Update code to use `X, y, categorical, names = dataset.get_data(target=...)`.

affects: >=0.14

deprecated`openml.datasets.list_datasets()` is deprecated; use `openml.datasets.get_dataset_list()` or pass parameters to `list_datasets()`.

fix

Replace `list_datasets()` with `get_dataset_list()` or use `list_datasets(size=...)` etc.

affects: >=0.14

gotchaAPI key configuration requires either setting OPENML_API_KEY env var or creating a ~/.openml/config file. Without it, many functions raise OpenMLServerError (401).

fix

Set env var or file: `openml.config.apikey = 'your_apikey'`. Get key from openml.org.

affects: all

Errors

Common errors & fixes

openml.exceptions.OpenMLServerError: The request has not been authorized (401)

Missing or invalid OpenML API key.

fix

Set API key via environment variable OPENML_API_KEY or openml.config.apikey = '...'

AttributeError: 'int' object has no attribute 'get' (when calling get_dataset with wrong ID)

Dataset ID does not exist or is not an integer. Function expects integer ID but may receive something else.

fix

Ensure dataset ID is valid integer. Use list_datasets() to check existing IDs.

ModuleNotFoundError: No module named 'openml'

OpenML not installed or installed in different environment.

fix

Run `pip install openml` and ensure correct Python environment is active.

Upgrade

Version history

0.15.1latest on PyPI · released Jan 25, 2025

Audit

Dependencies

pandasrequiredData handling for datasets and runs

requestsrequiredHTTP communication with OpenML server

scikit-learnrequiredMachine learning utilities (e.g., check_consistent_length)

xmltodictrequiredParsing XML responses from OpenML

liac-arffrequiredARFF file format support

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/openml/openml-python ↗

packagehttps://pypi.org/project/openml/ ↗

homepagehttps://openml.org/ ↗

docshttps://openml.github.io/openml-python/ ↗