548         try:

   548         try:

   549             self._list.remove(key)

   549             self._list.remove(key)

   550         except ValueError:

   550         except ValueError:

   551             pass

   551             pass

   552     def keys(self):

   552     def keys(self):

   554     def iterkeys(self):

   554     def iterkeys(self):

   555         return self._list.__iter__()

   555         return self._list.__iter__()

   556     def iteritems(self):

   556     def iteritems(self):

   557         for k in self._list:

   557         for k in self._list:

   558             yield k, self[k]

   558             yield k, self[k]