Traverse directory and find valid images

#!/usr/bin/env python
import os
from os.path import join
from PIL import Image

#print os.path.dirname(__file__)

for current_directory, sub_directories, files in os.walk('.'):
    #print "Current directory", current_directory
   
    #print "Sub directories", sub_directories
    
    for filename in files:
        path = os.path.join(current_directory, filename)
        
        try:
            trial_image = Image.open(path)
            trial_image.verify()
            print path + ' is a valid image file'
        except ImportError:
            # Under PyPy, it is possible to import PIL. However, the underlying
            # _imaging C module isn't available, so an ImportError will be
            # raised. Catch and re-raise.
            raise
        except: # Python Imaging Library doesn't recognize it as an image
            pass