code: def breadcrumb(self):
          
          if self.path == '.':
              return []
  
          path = self.path
          breadcrumb = [((self.url_ext or '.'), self.title)]
  
          while True:
              path = os.path.normpath(os.path.join(path, '..'))
              if path == '.':
                  break
  
              url = (url_from_path(os.path.relpath(path, self.path)) + '/' +
                     self.url_ext)
              breadcrumb.append((url, self.gallery.albums[path].title))
  
          breadcrumb.reverse()
          return breadcrumb
docs: List of ``(url, title)`` tuples defining the current breadcrumb
          path.