Python: Lock directory access under windows

def flock(fd, blocking=False, exclusive=False):

    if exclusive:
        flags = fcntl.LOCK_EX
    else:
        flags = fcntl.LOCK_SH
    if not blocking:
        flags |= fcntl.LOCK_NB
    fcntl.flock(fd, flags)

def flock(fd, blocking=False, exclusive=False):

    if blocking:
        flags = msvcrt.LK_NBLCK
    else:
        flags = msvcrt.LK_LOCK
    msvcrt.locking(fd.fileno(), flags, os.path.getsize(fd.name))

for file in os.listdir(dir):
 f = open(file)
 flock(f)

open(dirname)

OSError: [Errno 13] Permission denied: dirname