+ def count_messages(self):
+ """Estimate the number of messages matching the query
+
+ This function performs a search and returns Xapian's best
+ guess as to the number of matching messages. It is somewhat
+ faster than performing :meth:`search_messages` and counting
+ the result with `len()`. Technically, it wraps the underlying
+ *notmuch_query_count_messages* function.
+
+ :returns: :class:`Messages`
+ :exception: :exc:`NotmuchError`
+
+ * STATUS.NOT_INITIALIZED if query is not inited
+ """
+ if self._query is None:
+ raise NotmuchError(STATUS.NOT_INITIALIZED)
+
+ return Query._count_messages(self._query)