os.path.isfile doesn't reckognize a .picasa.ini file as a file
and os.path.isdir doesn't reckognize a directory as a directory

code:

def traverse (targetDir):
    currentDir = targetDir
    dirs = os.listdir(targetDir)
#    dirs = [x for x in os.listdir('.') if x.endswith('.JPG')]
    for entry in dirs:
        if os.path.isdir(entry):
            print("Traversing " + entry)
            traverse(entry)
        else:
            print("Not dir: " + entry)
            if os.path.isfile(entry):
                print("Processing " + " " + currentDir + " " + entry)
            else:
                print("Not file: " + entry)
    print("\n")
    return True

The test directory contains jpg files and a folder with some other jpgs and a subfolder containing jpgs