Pil

[menator01]

Please use correct tags when posting code.
This works for me

from os import walk
from PIL import Image

path = r'images'
copy_path = r'thumbs'
files = '*.png'
filename = []

for root, dir, files in walk(path):
    for img in files:
        try:
            image = Image.open(f'{path}/{img}')
            image.thumbnail((32,32))
            image.save(f'{copy_path}/thumb_{img}')
        except ValueError:
            print('Not a image')