os.path.walkup

# Similar to os.path.walk but traverses up the tree

def walkup(bottom=os.path.dirname(__file__)):
  """Similar to os.walk, but up the tree
  instead of down.
  """
  path = os.path.realpath(bottom)
  dirs = []
  files = []
  for item in os.listdir(path):
      abs_path = os.path.join(path, item)
      if os.path.isdir(abs_path):
          dirs.append(item)
      else:
          files.append(item)
  
  yield (path, dirs, files)
  
  up = os.path.realpath(os.path.join(bottom, '..'))
  
  if up == bottom:
      return
  
  for x in walkup(up):
      yield x