import glob
import PIL.Image

photos = glob.glob('photos/*.jpg')

for image in photos:
    print(image)
    img = PIL.Image.open(image)
    img.save(image.replace('.jpg', '.webp'))
    ratio = 400/max(img.height, img.width)
    img = img.resize((int(img.width * ratio), int(img.height * ratio)))
    image = image.replace('photos/', 'photos/thumbnail/').replace('.jpg', '.webp')
    img.save(image, quality=50, subsampling=2)