Prefixer

Prepends a prefix on features names.

Parameters

• prefix (str)

Examples

>>> from river import compose

>>> x = {'a': 42, 'b': 12}
>>> compose.Prefixer('prefix_').transform_one(x)
{'prefix_a': 42, 'prefix_b': 12}

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.