mlnext.pipeline.LengthTransformer¶

class mlnext.pipeline.LengthTransformer(pad_length: int | None = None, fill_value: int = 0, truncate: bool = False)[source]¶

Bases: BaseEstimator, TransformerMixin

Pad or truncates the input to an fixed length by either a set length or a fitted length.

Parameters:

pad_length (int | None) – Length to pad the data to. Default: None.
fill_value (int) – Value to pad data with. Default: 0.
truncate (bool) – Whether to truncate if the length exceeds pad_length. If False, an error is raised for an input longer than pad_length.

Added in version 0.6.0.

Example

>>> import pandas as pd
>>> from mlnext import LengthTransformer

>>> df = pd.DataFrame({'a': [0, 1, 2], 'b': [1, 2, 3]})
>>> t = LengthTransformer(pad_length=5, fill_value=-1)

>>> t.fit_transform(df)
    a   b
     0       1
     1       2
     2       3
-1  -1
-1  -1

Methods

`fit`	Sets the pad_length to the length of the fitted dataframe (if pad_length is not defined).
`fit_transform`	Fit to data, then transform it.
`get_metadata_routing`	Get metadata routing of this object.
`get_params`	Get parameters for this estimator.
`set_output`	Set output container.
`set_params`	Set the parameters of this estimator.
`transform`	Pads or truncates X to pad_length_.

fit(X: DataFrame, y=None)[source]¶

Sets the pad_length to the length of the fitted dataframe (if pad_length is not defined).

Parameters:

X (pd.DataFrame) – Data.
y (_type_, optional) – Labels (ignored). Defaults to None.

Returns:

Returns self.

Return type:

LengthTransformer

fit_transform(X, y=None, **fit_params)¶

Fit to data, then transform it.

Fits transformer to X and y with optional parameters fit_params and returns a transformed version of X.

Parameters:

X (array-like of shape (n_samples, n_features)) – Input samples.
y (array-like of shape (n_samples,) or (n_samples, n_outputs), default=None) – Target values (None for unsupervised transformations).
**fit_params (dict) – Additional fit parameters.

Returns:

X_new – Transformed array.

Return type:

ndarray array of shape (n_samples, n_features_new)

get_metadata_routing()¶

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)¶

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

set_output(*, transform=None)¶

Set output container.

See sphx_glr_auto_examples_miscellaneous_plot_set_output.py for an example on how to use the API.

Parameters:

transform ({"default", "pandas", "polars"}, default=None) –

Configure output of transform and fit_transform.

”default”: Default output format of a transformer
”pandas”: DataFrame output
”polars”: Polars output
None: Transform configuration is unchanged

Added in version 1.4: “polars” option was added.

Returns:

self – Estimator instance.

Return type:

estimator instance

set_params(**params)¶

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance

transform(X: DataFrame) → DataFrame[source]¶

Pads or truncates X to pad_length_.

Parameters:: X (pd.DataFrame) – Data.
Raises:: ValueError – Raised if X is longer than pad_length and truncate is False.
Returns:: Returns the new dataframe of length pad_length.
Return type:: pd.DataFrame