import matplotlib.pyplot as plt

plt.figure()
acc = []
for k in [1, 3, 5, 7, 9]:
    clr = Knn_classifier(train_images, train_labels)
    predicted_labels = clr.classify_images(test_images, k)
    acc.append(clr.accuracy_score(test_labels, predicted_labels))
print(acc)

plt.plot([1, 3, 5, 7, 9], acc)