def visit(self, node):
        """ Replace the placeholder if it is one or continue. """
        if isinstance(node, Placeholder):
            return self.placeholders[node.id]
        else:
            return super(PlaceholderReplace, self).visit(node)
def visit ( self , node ) : if isinstance ( node , Placeholder ) : return self . placeholders [ node . id ] else : return super ( PlaceholderReplace , self ) . visit ( node )
Replace the placeholder if it is one or continue.