Datasets¶

How to list and download datasets.

In [ ]:

import openml
import pandas as pd
from openml.datasets import edit_dataset, fork_dataset, get_dataset

import openml import pandas as pd from openml.datasets import edit_dataset, fork_dataset, get_dataset

Exercise 0¶

• List datasets

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datalist = openml.datasets.list_datasets()
datalist = datalist[["did", "name", "NumberOfInstances", "NumberOfFeatures", "NumberOfClasses"]]

print(f"First 10 of {len(datalist)} datasets...")
datalist.head(n=10)

# The same can be done with lesser lines of code
openml_df = openml.datasets.list_datasets()
openml_df.head(n=10)

datalist = openml.datasets.list_datasets() datalist = datalist[["did", "name", "NumberOfInstances", "NumberOfFeatures", "NumberOfClasses"]] print(f"First 10 of {len(datalist)} datasets...") datalist.head(n=10) # The same can be done with lesser lines of code openml_df = openml.datasets.list_datasets() openml_df.head(n=10)

Exercise 1¶

• Find datasets with more than 10000 examples.
• Find a dataset called 'eeg_eye_state'.
• Find all datasets with more than 50 classes.

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datalist[datalist.NumberOfInstances > 10000].sort_values(["NumberOfInstances"]).head(n=20)

datalist[datalist.NumberOfInstances > 10000].sort_values(["NumberOfInstances"]).head(n=20)

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datalist.query('name == "eeg-eye-state"')

datalist.query('name == "eeg-eye-state"')

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datalist.query("NumberOfClasses > 50")

datalist.query("NumberOfClasses > 50")

Download datasets¶

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# This is done based on the dataset ID.
dataset = openml.datasets.get_dataset(1471)

# Print a summary
print(
    f"This is dataset '{dataset.name}', the target feature is "
    f"'{dataset.default_target_attribute}'"
)
print(f"URL: {dataset.url}")
print(dataset.description[:500])

# This is done based on the dataset ID. dataset = openml.datasets.get_dataset(1471) # Print a summary print( f"This is dataset '{dataset.name}', the target feature is " f"'{dataset.default_target_attribute}'" ) print(f"URL: {dataset.url}") print(dataset.description[:500])

Get the actual data.

openml-python returns data as pandas dataframes (stored in the eeg variable below), and also some additional metadata that we don't care about right now.

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eeg, *_ = dataset.get_data()

eeg, *_ = dataset.get_data()

You can optionally choose to have openml separate out a column from the dataset. In particular, many datasets for supervised problems have a set default_target_attribute which may help identify the target variable.

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X, y, categorical_indicator, attribute_names = dataset.get_data(
    target=dataset.default_target_attribute
)
print(X.head())
print(X.info())

X, y, categorical_indicator, attribute_names = dataset.get_data( target=dataset.default_target_attribute ) print(X.head()) print(X.info())

Sometimes you only need access to a dataset's metadata. In those cases, you can download the dataset without downloading the data file. The dataset object can be used as normal. Whenever you use any functionality that requires the data, such as get_data, the data will be downloaded. Starting from 0.15, not downloading data will be the default behavior instead. The data will be downloading automatically when you try to access it through openml objects, e.g., using dataset.features.

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dataset = openml.datasets.get_dataset(1471)

dataset = openml.datasets.get_dataset(1471)

Exercise 2¶

• Explore the data visually.

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eegs = eeg.sample(n=1000)
_ = pd.plotting.scatter_matrix(
    X.iloc[:100, :4],
    c=y[:100],
    figsize=(10, 10),
    marker="o",
    hist_kwds={"bins": 20},
    alpha=0.8,
    cmap="plasma",
)

eegs = eeg.sample(n=1000) _ = pd.plotting.scatter_matrix( X.iloc[:100, :4], c=y[:100], figsize=(10, 10), marker="o", hist_kwds={"bins": 20}, alpha=0.8, cmap="plasma", )

Edit a created dataset¶

This example uses the test server, to avoid editing a dataset on the main server.

.. warning:: .. include:: ../../test_server_usage_warning.txt

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openml.config.start_using_configuration_for_example()

openml.config.start_using_configuration_for_example()

Edit non-critical fields, allowed for all authorized users: description, creator, contributor, collection_date, language, citation, original_data_url, paper_url

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desc = (
    "This data sets consists of 3 different types of irises' "
    "(Setosa, Versicolour, and Virginica) petal and sepal length,"
    " stored in a 150x4 numpy.ndarray"
)
did = 128
data_id = edit_dataset(
    did,
    description=desc,
    creator="R.A.Fisher",
    collection_date="1937",
    citation="The use of multiple measurements in taxonomic problems",
    language="English",
)
edited_dataset = get_dataset(data_id)
print(f"Edited dataset ID: {data_id}")

desc = ( "This data sets consists of 3 different types of irises' " "(Setosa, Versicolour, and Virginica) petal and sepal length," " stored in a 150x4 numpy.ndarray" ) did = 128 data_id = edit_dataset( did, description=desc, creator="R.A.Fisher", collection_date="1937", citation="The use of multiple measurements in taxonomic problems", language="English", ) edited_dataset = get_dataset(data_id) print(f"Edited dataset ID: {data_id}")

Editing critical fields (default_target_attribute, row_id_attribute, ignore_attribute) is allowed only for the dataset owner. Further, critical fields cannot be edited if the dataset has any tasks associated with it. To edit critical fields of a dataset (without tasks) owned by you, configure the API key: openml.config.apikey = 'FILL_IN_OPENML_API_KEY' This example here only shows a failure when trying to work on a dataset not owned by you:

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try:
    data_id = edit_dataset(1, default_target_attribute="shape")
except openml.exceptions.OpenMLServerException as e:
    print(e)

try: data_id = edit_dataset(1, default_target_attribute="shape") except openml.exceptions.OpenMLServerException as e: print(e)

Fork dataset¶

Used to create a copy of the dataset with you as the owner. Use this API only if you are unable to edit the critical fields (default_target_attribute, ignore_attribute, row_id_attribute) of a dataset through the edit_dataset API. After the dataset is forked, you can edit the new version of the dataset using edit_dataset.

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data_id = fork_dataset(1)
print(data_id)
data_id = edit_dataset(data_id, default_target_attribute="shape")
print(f"Forked dataset ID: {data_id}")

data_id = fork_dataset(1) print(data_id) data_id = edit_dataset(data_id, default_target_attribute="shape") print(f"Forked dataset ID: {data_id}")

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openml.config.stop_using_configuration_for_example()
# License: BSD 3-Clauses

openml.config.stop_using_configuration_for_example() # License: BSD 3-Clauses