Shi Mu: Before all you were doing was defining a function with: import os
def buildList( directory='c:\TEMP' ): dirs = [ ] listing = os.listdir(directory) for x in listing: x = os.path.join(directory, x) print x if os.path.isdir(x): dirs.append(x) return dirs when you python this file, it does not execute the function, it only defines it. Later Lundh told you to add: print buildList() to the end of the file. Not only does this execute buildList() but it also prints out the list "dirs" that buildList returns. So the first time it wasn't that "print x" wasn't printing anything, it was only that you weren't executing the function buildList(). If, at the end of the file, you put buildList() you will only see output values corresponding to the print x statement -- http://mail.python.org/mailman/listinfo/python-list