correct_sum = [] for i in range(1, 20): # Correct usage of range and for model = KNeighborsClassifier(n_neighbors=i) model.fit(x_train, y_train) pred = model.predict(x_test) correct = np.sum(pred == y_test) correct_sum.append(correct) print(correct_sum) i was typing this code block in jupyter notebook every thing is uptodate but it detects word "range" as "for" and "in", same theme color for all three words and this gives ourput like this when i call it [np.int64(25), np.int64(26), np.int64(28), np.int64(29), np.int64(28), ...] but i want an array like this [25, 26, 28,...] Restart the kernel in Jupyter Notebook. Re-run the code after restartin your text the kernel. Clear output: Sometimes, output errors or old code can mess with the current session. Continue reading...