y_scores = cross_val_predict(sgd_clf, X_train, y_train_5, cv=3, method="decision_function")

This code uses cross-validation to predict the decision scores of the SGDClassifier on the training data (X_train) for binary classification of whether the target variable (y_train_5) is equal to 5. The function cross_val_predict() uses k-fold cross-validation with cv=3, meaning that the training data is split into 3 equally sized folds, and the model is trained and tested on each fold in turn. The method="decision_function" parameter specifies that the decision scores rather than the predicted class labels should be returned. The resulting y_scores variable will contain the decision scores for each instance in the training data.