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Imputer

Copyright (c) 2015 The auto-sklearn developers. All rights reserved.

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ColumnSimpleImputer

Bases: BaseEstimator, TransformerMixin

Source code in tpot2/builtin_modules/imputer.py
class ColumnSimpleImputer(BaseEstimator, TransformerMixin):
    def __init__(self,  columns="all",         
                        missing_values=np.nan,
                        strategy="mean",
                        fill_value=None,
                        copy=True,
                        add_indicator=False,
                        keep_empty_features=False,):

        self.columns = columns
        self.missing_values = missing_values
        self.strategy = strategy
        self.fill_value = fill_value
        self.copy = copy
        self.add_indicator = add_indicator
        self.keep_empty_features = keep_empty_features


    def fit(self, X, y=None):
        """Fit OneHotEncoder to X, then transform X.

        Equivalent to self.fit(X).transform(X), but more convenient and more
        efficient. See fit for the parameters, transform for the return value.

        Parameters
        ----------
        X : array-like or sparse matrix, shape=(n_samples, n_features)
            Dense array or sparse matrix.
        y: array-like {n_samples,} (Optional, ignored)
            Feature labels
        """

        if (self.columns == "categorical" or self.columns == "numeric") and not isinstance(X, pd.DataFrame):
            raise ValueError(f"Invalid value for columns: {self.columns}. "
                             "Only 'all' or <list> is supported for np arrays")

        if self.columns == "categorical":
            self.columns_ = list(X.select_dtypes(exclude='number').columns)
        elif self.columns == "numeric":
            self.columns_ =  [col for col in X.columns if is_numeric_dtype(X[col])]
        elif self.columns == "all":
            if isinstance(X, pd.DataFrame):
                self.columns_ = X.columns
            else:
                self.columns_ = list(range(X.shape[1]))
        elif isinstance(self.columns, list):
            self.columns_ = self.columns
        else:
            raise ValueError(f"Invalid value for columns: {self.columns}")

        if len(self.columns_) == 0:
            return self

        self.imputer = sklearn.impute.SimpleImputer(missing_values=self.missing_values,
                                                    strategy=self.strategy,
                                                    fill_value=self.fill_value,
                                                    copy=self.copy,
                                                    add_indicator=self.add_indicator,
                                                    keep_empty_features=self.keep_empty_features)

        if isinstance(X, pd.DataFrame):
            self.imputer.set_output(transform="pandas")

        if isinstance(X, pd.DataFrame):
            self.imputer.fit(X[self.columns_], y)
        else:
            self.imputer.fit(X[:, self.columns_], y)

        return self

    def transform(self, X):
        """Transform X using one-hot encoding.

        Parameters
        ----------
        X : array-like or sparse matrix, shape=(n_samples, n_features)
            Dense array or sparse matrix.

        Returns
        -------
        X_out : sparse matrix if sparse=True else a 2-d array, dtype=int
            Transformed input.
        """
        if len(self.columns_) == 0:
            return X

        if isinstance(X, pd.DataFrame):
            X = X.copy()
            X[self.columns_] = self.imputer.transform(X[self.columns_])
            return X
        else:
            X = np.copy(X)
            X[:, self.columns_] = self.imputer.transform(X[:, self.columns_])
            return X

fit(X, y=None)

Fit OneHotEncoder to X, then transform X.

Equivalent to self.fit(X).transform(X), but more convenient and more efficient. See fit for the parameters, transform for the return value.

Parameters:

Name Type Description Default
X array-like or sparse matrix, shape=(n_samples, n_features)

Dense array or sparse matrix.

required
y

Feature labels

None
Source code in tpot2/builtin_modules/imputer.py
def fit(self, X, y=None):
    """Fit OneHotEncoder to X, then transform X.

    Equivalent to self.fit(X).transform(X), but more convenient and more
    efficient. See fit for the parameters, transform for the return value.

    Parameters
    ----------
    X : array-like or sparse matrix, shape=(n_samples, n_features)
        Dense array or sparse matrix.
    y: array-like {n_samples,} (Optional, ignored)
        Feature labels
    """

    if (self.columns == "categorical" or self.columns == "numeric") and not isinstance(X, pd.DataFrame):
        raise ValueError(f"Invalid value for columns: {self.columns}. "
                         "Only 'all' or <list> is supported for np arrays")

    if self.columns == "categorical":
        self.columns_ = list(X.select_dtypes(exclude='number').columns)
    elif self.columns == "numeric":
        self.columns_ =  [col for col in X.columns if is_numeric_dtype(X[col])]
    elif self.columns == "all":
        if isinstance(X, pd.DataFrame):
            self.columns_ = X.columns
        else:
            self.columns_ = list(range(X.shape[1]))
    elif isinstance(self.columns, list):
        self.columns_ = self.columns
    else:
        raise ValueError(f"Invalid value for columns: {self.columns}")

    if len(self.columns_) == 0:
        return self

    self.imputer = sklearn.impute.SimpleImputer(missing_values=self.missing_values,
                                                strategy=self.strategy,
                                                fill_value=self.fill_value,
                                                copy=self.copy,
                                                add_indicator=self.add_indicator,
                                                keep_empty_features=self.keep_empty_features)

    if isinstance(X, pd.DataFrame):
        self.imputer.set_output(transform="pandas")

    if isinstance(X, pd.DataFrame):
        self.imputer.fit(X[self.columns_], y)
    else:
        self.imputer.fit(X[:, self.columns_], y)

    return self

transform(X)

Transform X using one-hot encoding.

Parameters:

Name Type Description Default
X array-like or sparse matrix, shape=(n_samples, n_features)

Dense array or sparse matrix.

required

Returns:

Name Type Description
X_out sparse matrix if sparse=True else a 2-d array, dtype=int

Transformed input.

Source code in tpot2/builtin_modules/imputer.py
def transform(self, X):
    """Transform X using one-hot encoding.

    Parameters
    ----------
    X : array-like or sparse matrix, shape=(n_samples, n_features)
        Dense array or sparse matrix.

    Returns
    -------
    X_out : sparse matrix if sparse=True else a 2-d array, dtype=int
        Transformed input.
    """
    if len(self.columns_) == 0:
        return X

    if isinstance(X, pd.DataFrame):
        X = X.copy()
        X[self.columns_] = self.imputer.transform(X[self.columns_])
        return X
    else:
        X = np.copy(X)
        X[:, self.columns_] = self.imputer.transform(X[:, self.columns_])
        return X