root = '101_ObjectCategories'
exclude = ['BACKGROUND_Google', 'Motorbikes', 'airplanes', 'Faces_easy', 'Faces']
train_split, val_split = 0.7, 0.15

categories = [x[0] for x in os.walk(root) if x[0]][1:]
categories = [c for c in categories if c not in [os.path.join(root, e) for e in exclude]]

print(categories)