import pywikibot
from pywikibot import pagegenerators
from IPython.display import Image
from IPython.core.display import HTML
site = pywikibot.Site('commons', 'commons')
cat = pywikibot.Category(site, 'Category:Barnacle_Goose')
gen = pagegenerators.CategorizedPageGenerator(cat)
for page in gen:
url = page.get_file_url()
if url.lower().endswith(".jpg"):
display(Image(url,width=100, height=100))
print("done")