def scale_edges(self, multiplier):
        '''Multiply all edges in this ``Tree`` by ``multiplier``'''
        if not isinstance(multiplier,int) and not isinstance(multiplier,float):
            raise TypeError("multiplier must be an int or float")
        for node in self.traverse_preorder():
            if node.edge_length is not None:
                node.edge_length *= multiplier
def scale_edges ( self , multiplier ) : if not isinstance ( multiplier , int ) and not isinstance ( multiplier , float ) : raise TypeError ( "multiplier must be an int or float" ) for node in self . traverse_preorder ( ) : if node . edge_length is not None : node . edge_length *= multiplier
Multiply all edges in this ``Tree`` by ``multiplier``