Python sklearn pipline helpers

utils.py

from sklearn.base import TransformerMixin


class TransformWrapper(TransformerMixin):
    """simple wrapper for instruments like LabelEncoder.
    It is usefull if we want to encode many features at one time. 
    They have a little bit different interface compairing to OneHotEncoder for example"""

    def __init__(self, enc):
        self.enc = enc
    def fit(self, X, y=None):

        self.d = {}
        for col in X.columns:
            self.d[col] = self.enc()
            self.d[col].fit(X[col].values)
        return self
        
    def transform(self, X, y=None):

        l = list()
        for col in X.columns:
            l.append(self.d[col].transform(X[col].values).reshape(-1,1))
        result = np.hstack(l)
        return result