title: What is the difference between ImageDataGenerator.flow() and ImageDataGenerator.flow_from_directory()?
body: <p><code>datagen = ImageDataGenerator(rotation_range = 20, zoom_range = 15, width_shift_range=0.2, height_shift_range=0.2, shear_range=0.15, horizontal_flip=True, vertical_flip=True, fill_mode='nearest')</code></p>
  <p>What is the difference between <code>datagen.flow()</code> and <code>datagen.flow_from_directory</code>?</p>