parameters: (self, cat_path, title=None)
docstring: :param cat_path: A list or tuple of the path to this category
          :param title: optional - name of text.  If present tries to return a text
          :return: TocNode
docstring_summary: :param cat_path: A list or tuple of the path to this category
          :param title: optional - name of text.  If present tries to return a text
          :return: TocNode
docstring_tokens: : param cat_path : A list or tuple of the path to this category : param title : optional - name of text . If present tries to return a text : return : TocNode
function: def lookup(self, cat_path, title=None):
          """
          :param cat_path: A list or tuple of the path to this category
          :param title: optional - name of text.  If present tries to return a text
          :return: TocNode
          """
          path = tuple(cat_path)
          if title is not None:
              path += tuple([title])
          try:
              return self._path_hash[path]
          except KeyError:
              # todo: remove this try, after getting rid of the "Other" cat.
              try:
                  return self._path_hash[tuple(["Other"]) + path]
              except KeyError:
                  return None
function_tokens: def lookup ( self , cat_path , title = None ) : path = tuple ( cat_path ) if title is not None : path += tuple ( [ title ] ) try : return self . _path_hash [ path ] except KeyError : # todo: remove this try, after getting rid of the "Other" cat. try : return self . _path_hash [ tuple ( [ "Other" ] ) + path ] except KeyError : return None