dependent_widgets.py

# Create widgets
directory = widgets.Dropdown(options=['images', 'nature', 'assorted'])
images = widgets.Dropdown(options=os.listdir(directory.value))

# Updates the image options based on directory value
def update_images(*args):
    images.options = os.listdir(directory.value)

# Tie the image options to directory value
directory.observe(update_images, 'value')

# Show the images
def show_images(fdir, file):
    display(Image(f'{fdir}/{file}'))

_ = interact(show_images, fdir=directory, file=images)