(self, start, end)
return chow_number
Estimate how far start is from end.
        
        @type  start: node
        @param start: Start node.
        
        @type  end: node
        @param end: End node.
Estimate how far start is from end.
Estimate how far start is from end .
def __call__(self, start, end):
        """
        Estimate how far start is from end.
        
        @type  start: node
        @param start: Start node.
        
        @type  end: node
        @param end: End node.
        """
        assert len( list(self.nodes.keys()) ) > 0, "You need to optimize this heuristic for your graph before it can be used to estimate."
                
        cmp_sequence = list(zip( self.nodes[start], self.nodes[end] ))
        chow_number = max( abs( a-b ) for a,b in cmp_sequence )
        return chow_number
def __call__ ( self , start , end ) : assert len ( list ( self . nodes . keys ( ) ) ) > 0 , "You need to optimize this heuristic for your graph before it can be used to estimate." cmp_sequence = list ( zip ( self . nodes [ start ] , self . nodes [ end ] ) ) chow_number = max ( abs ( a - b ) for a , b in cmp_sequence ) return chow_number