cross-validation

from sklearn.preprocessing import StandardScaler, PolynomialFeatures
from sklearn.model_selection import KFold, cross_val_predict
from sklearn.linear_model import LinearRegression, Lasso, Ridge
from sklearn.metrics import r2_score
from sklearn.pipeline import Pipeline

kf = KFold(shuffle=True, random_state=72018, n_splits=3)

X = data.drop('SalePrice', axis=1)
y = data.SalePrice