- def __len__(self):
- """len(:class:`Tags`) returns the number of contained tags
-
- .. note:: As this iterates over the tags, we will not be able
- to iterate over them again (as in retrieve them)! If
- the tags have been exhausted already, this will raise a
- :exc:`NotmuchError` STATUS.NOT_INITIALIZED on
- subsequent attempts.
- """
- if self._tags is None:
- raise NotmuchError(STATUS.NOT_INITIALIZED)
-
- i = 0
- while nmlib.notmuch_tags_valid(self._tags):
- nmlib.notmuch_tags_move_to_next(self._tags)
- i += 1
- self._tags = None
- return i
-