Renamer

Renames features following substitution rules.

Parameters

• mapping

  Type → dict[str, str]

  Dictionnary describing substitution rules. Keys in mapping that are not a feature's name are silently ignored.

Examples

from river import compose

mapping = {'a': 'v', 'c': 'o'}
x = {'a': 42, 'b': 12}
compose.Renamer(mapping).transform_one(x)

{'b': 12, 'v': 42}

Methods

learn_one

Update with a set of features x.

A lot of transformers don't actually have to do anything during the learn_one step because they are stateless. For this reason the default behavior of this function is to do nothing. Transformers that however do something during the learn_one can override this method.

Parameters

• x — 'dict'

Returns

Transformer: self

transform_one

Transform a set of features x.

Parameters

• x — 'dict'

Returns

dict: The transformed values.