fix: add missing str formatting operator

Author: pprett

examples/semi_supervised/plot_label_propagation_digits_active_learning.py

@@ -56,7 +56,7 @@
     cm = confusion_matrix(true_labels, predicted_labels,
                           labels=lp_model.classes_)
 
-    print('Iteration %i %s' (i, 70 * '_'))
+    print('Iteration %i %s' % (i, 70 * '_'))
     print("Label Spreading model: %d labeled & %d unlabeled (%d total)"
           % (n_labeled_points, n_total_samples - n_labeled_points, n_total_samples))