old_contents: def normpath(path):
      """Normalize path, eliminating double slashes, etc."""
      comps = path.split('/')
      new_comps = []
      for comp in comps:
          if comp == '':
              continue
          if comp in ('.', '..'):
              raise ValueError('relative paths not allowed')
          new_comps.append(comp)
      slash = u'/' if isinstance(path, unicode) else '/'
      new_path = slash.join(new_comps)
      if path.startswith('/'):
          return slash + new_path
      return new_path
  
  
  def join(a, *p):
      """Join two or more pathname components, inserting '/' as needed.
  
      If any component is an absolute path, all previous path components
      will be discarded.
  
      """
      path = a
      for b in p:
          if b.startswith('/'):
              path = b
          elif path == '' or path.endswith('/'):
              path += b
          else:
              path += '/' + b
      return path
  
  
  def isabs(s):
      """Test whether a path is absolute"""
      return s.startswith('/')
  
  
  def basename(p):
      """Returns the final component of a pathname"""
      i = p.rfind('/') + 1
      return p[i:]
  
  
  def _prefix_root(root, path):
      """Prepend a root to a path. """
      return normpath(join(_norm_root(root), path.lstrip('/')))
  
  
  def _norm_root(root):
      return normpath(join('/', root))
  
new_contents: def normpath(path):
      """Normalize path, eliminating double slashes, etc."""
      comps = path.split('/')
      new_comps = []
      for comp in comps:
          if comp == '':
              continue
          if comp in ('.', '..'):
              raise ValueError('relative paths not allowed')
          new_comps.append(comp)
      new_path = '/'.join(new_comps)
      if path.startswith('/'):
          return '/' + new_path
      return new_path
  
  
  def join(a, *p):
      """Join two or more pathname components, inserting '/' as needed.
  
      If any component is an absolute path, all previous path components
      will be discarded.
  
      """
      path = a
      for b in p:
          if b.startswith('/'):
              path = b
          elif path == '' or path.endswith('/'):
              path += b
          else:
              path += '/' + b
      return path
  
  
  def isabs(s):
      """Test whether a path is absolute"""
      return s.startswith('/')
  
  
  def basename(p):
      """Returns the final component of a pathname"""
      i = p.rfind('/') + 1
      return p[i:]
  
  
  def _prefix_root(root, path):
      """Prepend a root to a path. """
      return normpath(join(_norm_root(root), path.lstrip('/')))
  
  
  def _norm_root(root):
      return normpath(join('/', root))
  
subject: remove weird u'' vs. '' code