AddMissingIndicator#
- class feature_engine.imputation.AddMissingIndicator(missing_only=True, variables=None)[source]#
The AddMissingIndicator() adds binary variables that indicate if data is missing (one indicator per variable). The added variables (missing indicators) are named with the original variable name plus ‘_na’.
The AddMissingIndicator() works for both numerical and categorical variables. You can pass a list with the variables for which the missing indicators should be added. Alternatively, the imputer will select and add missing indicators to all variables in the training set.
Note If
missing_only=True
, the imputer will add missing indicators only to those variables that show missing data duringfit()
. These may be a subset of the variables you indicated invariables
.More details in the User Guide.
- Parameters
- missing_only: bool, default=True
If missing indicators should be added to variables with missing data or to all variables.
True: indicators will be created only for those variables that showed missing data during
fit()
.False: indicators will be created for all variables
- variables: list, default=None
The list of variables to impute. If None, the imputer will find and select all variables.
- Attributes
- variables_:
List of variables for which the missing indicators will be created.
- feature_names_in_:
List with the names of features seen during
fit
.- n_features_in_:
The number of features in the train set used in fit.
Examples
>>> import pandas as pd >>> import numpy as np >>> from feature_engine.imputation import AddMissingIndicator >>> X = pd.DataFrame(dict( >>> x1 = [np.nan,1,1,0,np.nan], >>> x2 = ["a", np.nan, "b", np.nan, "a"], >>> )) >>> ami = AddMissingIndicator() >>> ami.fit(X) >>> ami.transform(X) x1 x2 x1_na x2_na 0 NaN a 1 0 1 1.0 NaN 0 1 2 1.0 b 0 0 3 0.0 NaN 0 1 4 NaN a 1 0
Methods
fit:
Find the variables for which the missing indicators will be created
fit_transform:
Fit to data, then transform it.
get_feature_names_out:
Get output feature names for transformation.
get_params:
Get parameters for this estimator.
set_params:
Set the parameters of this estimator.
transform:
Add the missing indicators.
- fit(X, y=None)[source]#
Learn the variables for which the missing indicators will be created.
- Parameters
- X: pandas dataframe of shape = [n_samples, n_features]
The training dataset.
- y: pandas Series, default=None
y is not needed in this imputation. You can pass None or y.
- fit_transform(X, y=None, **fit_params)[source]#
Fit to data, then transform it.
Fits transformer to
X
andy
with optional parametersfit_params
and returns a transformed version ofX
.- Parameters
- Xarray-like of shape (n_samples, n_features)
Input samples.
- yarray-like of shape (n_samples,) or (n_samples, n_outputs), default=None
Target values (None for unsupervised transformations).
- **fit_paramsdict
Additional fit parameters.
- Returns
- X_newndarray array of shape (n_samples, n_features_new)
Transformed array.
- get_feature_names_out(input_features=None)[source]#
Get output feature names for transformation. In other words, returns the variable names of transformed dataframe.
- Parameters
- input_featuresarray or list, default=None
This parameter exits only for compatibility with the Scikit-learn pipeline.
If
None
, thenfeature_names_in_
is used as feature names in.If an array or list, then
input_features
must matchfeature_names_in_
.
- Returns
- feature_names_out: list
Transformed feature names.
- get_metadata_routing()[source]#
Get metadata routing of this object.
Please check User Guide on how the routing mechanism works.
- Returns
- routingMetadataRequest
A
MetadataRequest
encapsulating routing information.
- get_params(deep=True)[source]#
Get parameters for this estimator.
- Parameters
- deepbool, default=True
If True, will return the parameters for this estimator and contained subobjects that are estimators.
- Returns
- paramsdict
Parameter names mapped to their values.
- set_params(**params)[source]#
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
- **paramsdict
Estimator parameters.
- Returns
- selfestimator instance
Estimator instance.