[ENH] Simplified Unified Get/List API

[Omswastik-11]

Redundant syntax for getters

In getters, syntax is repeated and redundant, mainly through
the submodule having to be imported or addressed.

import openml

# List all datasets and their properties
openml.datasets.list_datasets(output_format="dataframe")

# Get dataset by ID
dataset = openml.datasets.get_dataset(61)

# Get dataset by name
dataset = openml.datasets.get_dataset('Fashion-MNIST')

# This is similar for flows, runs, studies, such as

study = openml.studies.get_study(42)
flow = openml.flows.get_flows(42)

API implementation

import openml

# List all datasets
datasets_df = openml.list_all("dataset", output_format="dataframe")

# Get dataset by ID
dataset = openml.get("dataset", 61)

# Get dataset by name
dataset = openml.get("dataset", "Fashion-MNIST")

# Get task
task = openml.get("task", 31)

# Get flow
flow = openml.get("flow", 10)

# Get run
run = openml.get("run", 20)

# Shortcut: infer dataset from name when no type specified
dataset = openml.get("Fashion-MNIST")

Implementation Details

• Added openml.list_all(object_type: str, **kwargs) -> Any, a dispatcher that forwards to:

  • list_datasets
  • list_tasks
  • list_flows
  • list_runs

• Added openml.get(object_type_or_name, identifier=None, **kwargs) -> Any, a unified getter with support for:

  • Type-based lookup

    openml.get("dataset", 61)
    openml.get("dataset", "dataset_name")

  • Name-only shortcut for datasets

    openml.get("Fashion-MNIST")

• Exported both functions via __all__ and documented them with docstrings.

• Preserved full backward compatibility:

  • Existing submodule APIs (e.g., openml.datasets.get_dataset) remain unchanged.

• Added unit tests to validate dispatcher behavior without requiring network access.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 50.00000% with 14 lines in your changes missing coverage. Please review.
✅ Project coverage is 53.08%. Comparing base (d421b9e) to head (6cddeac).

Files with missing lines	Patch %	Lines
openml/dispatchers.py	48.14%	14 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1552      +/-   ##
==========================================
+ Coverage   52.04%   53.08%   +1.04%     
==========================================
  Files          36       37       +1     
  Lines        4333     4361      +28     
==========================================
+ Hits         2255     2315      +60     
+ Misses       2078     2046      -32     

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