The code is:

X_train, X_test, y_train, y_test = train_test_split(X, y)

try:

scaler = StandardScaler()

scaler.fit(X_train)

X_train_scaled = scaler.transform(X_train)

X_test_scaled = scaler.transform(X_test)

except ValueError:

pass

try:

baseline = y_train.median() #median train

print('If we just take the median value, our baseline, we would say that an overnight stay in Brasov costs: ’ + str(baseline))

except AttributeError:

pass

baseline_error = np.sqrt(mean_squared_error(y_pred=np.ones_like(y_test) * baseline, y_true=y_test))

print('And we will be right ± ’ + str(baseline_error))

lr = LinearRegression()

alphas = [1000, 100, 50, 20, 10, 1, 0.1, 0.01]

l1_ratios = [0.001, 0.01, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9]

ridge = RidgeCV(alphas=alphas)

lasso = LassoCV(alphas=alphas, max_iter=10000)

elastic = ElasticNetCV(alphas=alphas, l1_ratio=l1_ratios)

try:

for model, name in zip([lr, ridge, lasso, elastic], [‘LinearRegression’, ‘Ridge’, ‘Lasso’, ‘ElasticNet’]):

model.fit(X_train, y_train)

y_pred_train = model.predict(X_train_scaled)

mrse_train = np.sqrt(mean_squared_error(y_pred=y_pred_train, y_true=y_train))

y_pred = model.predict(X_test_scaled)

mrse_test = np.sqrt(mean_squared_error(y_pred=y_pred, y_true=y_test))

best_alpha = ‘’

if name != ‘LinearRegression’:

best_alpha = ’ best alpha: ’ + str(model.alpha_)

best_l1 = ‘’

if name == ‘ElasticNet’:

best_l1 = ’ best l1: '+ str(model.l1_ratio_)

print(name + ’ mrse_train: ’ + str(mrse_train) + ', mrse_test: ’ + str(mrse_test) + best_alpha + best_l1)

except ValueError:

pass

y_pred_train = lasso.predict(X_train_scaled)

diff = y_train - y_pred_train

plt.figure(figsize=(15,8))

plt.scatter(np.arange(len(diff)), diff, label = ‘residuals’)

plt.legend()

NameError Traceback (most recent call last)

in

----> 1 y_pred_train = lasso.predict(X_train_scaled)

2 diff = y_train - y_pred_train

3 plt.figure(figsize=(15,8))

4 plt.scatter(np.arange(len(diff)), diff, label = ‘residuals’)

5 plt.legend()

NameError: name ‘X_train_scaled’ is not defined or Search Results OR

AttributeError: LassoCV object has no attribute 'coef_