TranspileLayout

class qiskit.transpiler.TranspileLayout(initial_layout, input_qubit_mapping, final_layout=None)

Bases : object

Layout attributes from output circuit from transpiler.

The transpiler in general is unitary-perserving up to permutations caused by setting and applying initial layout during the Layout Stage and SwapGate insertion during the Routing Stage. To provide an interface to reason about these permutations caused by the transpiler.

There are three attributes associated with the class:

• initial_layout - This attribute is used to model the permutation caused by the Layout Stage it contains a Layout object that maps the input QuantumCircuits Qubit objects to the position in the output QuantumCircuit.qubits list.

• input_qubit_mapping - This attribute is used to retain input ordering of the original QuantumCircuit object. It maps the virtual Qubit object from the original circuit (and initial_layout) to its corresponding position in QuantumCircuit.qubits in the original circuit. This is needed when computing the permutation of the Operator of the circuit (and used by Operator.from_circuit()).

• final_layout - This is a Layout object used to model the output permutation caused ny any SwapGates inserted into the :class:~.QuantumCircuit` during the Routing Stage. It maps the output circuit’s qubits from QuantumCircuit.qubits to the final position after routing.

Attributes

final_layout: Layout | None = None

initial_layout: Layout

input_qubit_mapping: dict[Qubit, int]