(self)
return len(list(self.itervisible()))
Return how many `~.BoundColumn` objects are contained (and visible).
Return how many `~.BoundColumn` objects are contained (and visible).
Return how many ~ . BoundColumn objects are contained ( and visible ) .
def __len__(self):
        """Return how many `~.BoundColumn` objects are contained (and visible)."""
        return len(list(self.itervisible()))
def __len__ ( self ) : return len ( list ( self . itervisible ( ) ) )