[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("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(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.

[fkiraly]

you should really stop abusing try/except for case distinctions.
This is not good style, since you cannot distinguish actual exceptions from the try-block with the intended exception.

Instead, use if/else with a precise condition. In this case, you can also:

• use dict.get, and then check if None was retrieved.
• do an input check on object_type

[fkiraly]

the first arg can be two different things, I would avoid that - instead, I would do one of two things:

• use *, the argument syntax
• make the identifier first, and object_type second

[fkiraly]

again a try/except that you should avoid.

[fkiraly]

why are you changing this?

[fkiraly]

list is not a good name, as it overloads python list - we should avoid that!

[fkiraly]

what other good names are there?

[fkiraly]

maybe list_all