FilterOpNodes

class qiskit.transpiler.passes.FilterOpNodes(*args, **kwargs)

Bases: TransformationPass

Remove all operations that match a filter function

This transformation pass is used to remove any operations that matches a the provided filter function.

Parameters

predicate – A given callable that will be passed the DAGOpNode for each node in the DAGCircuit. If the callable returns True the DAGOpNode is retained in the circuit and if it returns False it is removed from the circuit.

Example

Filter out operations that are labelled "foo"

from qiskit import QuantumCircuit
from qiskit.transpiler.passes import FilterOpNodes
 
circuit = QuantumCircuit(1)
circuit.x(0, label='foo')
circuit.barrier()
circuit.h(0)
 
circuit = FilterOpNodes(
    lambda node: getattr(node.op, "label") != "foo"
)(circuit)
circuit.draw('mpl')

../_images/qiskit-transpiler-passes-FilterOpNodes-1.png

Attributes

is_analysis_pass

Check if the pass is an analysis pass.

If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.

is_transformation_pass

Check if the pass is a transformation pass.

If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).

Methods

execute

execute(passmanager_ir, state, callback=None)

GitHub

Execute optimization task for input Qiskit IR.

Parameters

passmanager_ir (Any) – Qiskit IR to optimize.
state (PassManagerState) – State associated with workflow execution by the pass manager itself.
callback (Callable | None) – A callback function which is caller per execution of optimization task.