python iterate directory

import os
directory = 'the/directory/you/want/to/use'

for filename in os.listdir(directory):
    if filename.endswith(".txt"):
      #do smth
      continue
    else:
    continue

import os

directory = r'C:\Users\admin'
for filename in os.listdir(directory):
    if filename.endswith(".jpg") or filename.endswith(".png"):
        print(os.path.join(directory, filename))
    else:
        continue

import os

for filename in os.listdir(directory):
	print(filename)