getsize issue (pyfakefs returns, Python fails with OSError)

[agroce]

import shutil
import pyfakefs.fake_filesystem
import os

ROOT_PATH = "/Volumes/ramdisk/newtest"

fs = pyfakefs.fake_filesystem.FakeFilesystem()
fs.CreateDirectory('/Volumes')
fs.CreateDirectory('/Volumes/ramdisk')
fs.CreateDirectory('/Volumes/ramdisk/newtest')
os0 = pyfakefs.fake_filesystem.FakeOsModule(fs)
opener0 = pyfakefs.fake_filesystem.FakeFileOpen(fs)

if False:
    os0 = os
    opener0 = open
    shutil.rmtree(ROOT_PATH)
    os.mkdir(ROOT_PATH)

component0 = "alpha"
path0 = ROOT_PATH
path0 += os.path.sep + component0 
file0 = opener0(path0,'w') 
component0 = "" 
path0 += os.path.sep + component0
result = os0.path.getsize(path0) 

Python says:

Traceback (most recent call last):
  File "getsizebug.py", line 26, in <module>
    result = os0.path.getsize(path0) 
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/genericpath.py", line 57, in getsize
    return os.stat(filename).st_size
OSError: [Errno 20] Not a directory: '/Volumes/ramdisk/newtest/alpha/'