qiskit/dagcircuit/dagcircuit.py
def op_nodes(self, op=None):
        """Get the list of "op" nodes in the dag.

        Args:
            op (Type): Instruction subclass op nodes to return. if op=None, return
                all op nodes.
        Returns:
            list[DAGNode]: the list of node ids containing the given op.
        """
        nodes = []
        for node in self._multi_graph.nodes():
            if node.type == "op":
                if op is None or isinstance(node.op, op):
                    nodes.append(node)
        return nodes
def op_nodes(self, op=None):
        nodes = []
        for node in self._multi_graph.nodes():
            if node.type == "op":
                if op is None or isinstance(node.op, op):
                    nodes.append(node)
        return nodes
def op_nodes ( self , op = None ) : nodes = [ ] for node in self . _multi_graph . nodes ( ) : if node . type == "op" : if op is None or isinstance ( node . op , op ) : nodes . append ( node ) return nodes
Get the list of "op" nodes in the dag.

        Args:
            op (Type): Instruction subclass op nodes to return. if op=None, return
                all op nodes.
        Returns:
            list[DAGNode]: the list of node ids containing the given op.
Get the list of op nodes in the dag .