get_routing_for_object

sklearn.utils.metadata_routing.get_routing_for_object(obj=None)

Get a Metadata{Router, Request} instance from the given object.

This function returns a MetadataRouter or a MetadataRequest from the given input.

This function always returns a copy or a new instance constructed from the input, such that changing the output of this function will not change the original object.

Added in version 1.3.

Parameters:

objobject

• If the object provides a get_metadata_routing method, return a copy

  of the output of that method.

• If the object is already a

  MetadataRequest or a MetadataRouter, return a copy of that.

• Returns an empty MetadataRequest

  otherwise.

Returns:

objMetadataRequest or MetadataRouter

A MetadataRequest or a MetadataRouter taken or created from the given object.

Examples

>>> from sklearn.datasets import make_classification
>>> from sklearn.pipeline import Pipeline
>>> from sklearn.preprocessing import StandardScaler
>>> from sklearn.linear_model import LogisticRegressionCV
>>> from sklearn.utils.metadata_routing import get_routing_for_object
>>> X, y = make_classification()
>>> pipe = Pipeline(
...       [("scaler", StandardScaler()), ("lr_cv", LogisticRegressionCV())]
... )
>>> pipe.fit(X, y)
Pipeline(steps=[('scaler', StandardScaler()), ('lr_cv', LogisticRegressionCV())])
>>> type(get_routing_for_object(pipe))
<class 'sklearn.utils._metadata_requests.MetadataRouter'>
>>> type(get_routing_for_object(pipe.named_steps.scaler))
<class 'sklearn.utils._metadata_requests.MetadataRequest'>
>>> type(get_routing_for_object(pipe.named_steps.lr_cv))
<class 'sklearn.utils._metadata_requests.MetadataRouter'>