--- title: NLocal (v2.0) description: API reference for qiskit.circuit.library.NLocal in qiskit v2.0 source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/2.0/qiskit.circuit.library.NLocal --- # NLocal *class* `qiskit.circuit.library.NLocal(num_qubits=None, rotation_blocks=None, entanglement_blocks=None, entanglement=None, reps=1, insert_barriers=False, parameter_prefix='θ', overwrite_block_parameters=True, skip_final_rotation_layer=False, skip_unentangled_qubits=False, initial_state=None, name='nlocal', flatten=None)` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L268-L1242) Bases: `BlueprintCircuit` The n-local circuit class. The structure of the n-local circuit are alternating rotation and entanglement layers. In both layers, parameterized circuit-blocks act on the circuit in a defined way. In the rotation layer, the blocks are applied stacked on top of each other, while in the entanglement layer according to the `entanglement` strategy. The circuit blocks can have arbitrary sizes (smaller equal to the number of qubits in the circuit). Each layer is repeated `reps` times, and by default a final rotation layer is appended. For instance, a rotation block on 2 qubits and an entanglement block on 4 qubits using `'linear'` entanglement yields the following circuit. ```text ┌──────┐ ░ ┌──────┐ ░ ┌──────┐ ┤0 ├─░─┤0 ├──────────────── ... ─░─┤0 ├ │ Rot │ ░ │ │┌──────┐ ░ │ Rot │ ┤1 ├─░─┤1 ├┤0 ├──────── ... ─░─┤1 ├ ├──────┤ ░ │ Ent ││ │┌──────┐ ░ ├──────┤ ┤0 ├─░─┤2 ├┤1 ├┤0 ├ ... ─░─┤0 ├ │ Rot │ ░ │ ││ Ent ││ │ ░ │ Rot │ ┤1 ├─░─┤3 ├┤2 ├┤1 ├ ... ─░─┤1 ├ ├──────┤ ░ └──────┘│ ││ Ent │ ░ ├──────┤ ┤0 ├─░─────────┤3 ├┤2 ├ ... ─░─┤0 ├ │ Rot │ ░ └──────┘│ │ ░ │ Rot │ ┤1 ├─░─────────────────┤3 ├ ... ─░─┤1 ├ └──────┘ ░ └──────┘ ░ └──────┘ | | +---------------------------------+ repeated reps times ``` If specified, barriers can be inserted in between every block. If an initial state object is provided, it is added in front of the NLocal. > **See also** > > The [`n_local()`](/docs/api/qiskit/2.0/qiskit.circuit.library.n_local "qiskit.circuit.library.n_local") function constructs a functionally equivalent circuit, but faster. > **Deprecated since version 1.3\_pending** > > The class `qiskit.circuit.library.n_local.n_local.NLocal` is pending deprecation as of Qiskit 1.3. It will be marked deprecated in a future release, and then removed no earlier than 3 months after the release date. Use the function qiskit.circuit.library.n\_local instead. **Parameters** - **num\_qubits** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) – The number of qubits of the circuit. - **rotation\_blocks** ([*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit")*] |* [*qiskit.circuit.Instruction*](/docs/api/qiskit/2.0/qiskit.circuit.Instruction "qiskit.circuit.Instruction") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*qiskit.circuit.Instruction*](/docs/api/qiskit/2.0/qiskit.circuit.Instruction "qiskit.circuit.Instruction")*] | None*) – The blocks used in the rotation layers. If multiple are passed, these will be applied one after another (like new sub-layers). - **entanglement\_blocks** ([*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit")*] |* [*qiskit.circuit.Instruction*](/docs/api/qiskit/2.0/qiskit.circuit.Instruction "qiskit.circuit.Instruction") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*qiskit.circuit.Instruction*](/docs/api/qiskit/2.0/qiskit.circuit.Instruction "qiskit.circuit.Instruction")*] | None*) – The blocks used in the entanglement layers. If multiple are passed, these will be applied one after another. To use different entanglements for the sub-layers, see [`get_entangler_map()`](#qiskit.circuit.library.NLocal.get_entangler_map "qiskit.circuit.library.NLocal.get_entangler_map"). - **entanglement** ([*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] |* [*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*]] | None*) – The indices specifying on which qubits the input blocks act. If `None`, the entanglement blocks are applied at the top of the circuit. - **reps** ([*int*](https://docs.python.org/3/library/functions.html#int)) – Specifies how often the rotation blocks and entanglement blocks are repeated. - **insert\_barriers** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – If `True`, barriers are inserted in between each layer. If `False`, no barriers are inserted. - **parameter\_prefix** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) – The prefix used if default parameters are generated. - **overwrite\_block\_parameters** ([*bool*](https://docs.python.org/3/library/functions.html#bool) *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*Parameter*](/docs/api/qiskit/2.0/qiskit.circuit.Parameter "qiskit.circuit.Parameter")*]]*) – If the parameters in the added blocks should be overwritten. If `False`, the parameters in the blocks are not changed. - **skip\_final\_rotation\_layer** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – Whether a final rotation layer is added to the circuit. - **skip\_unentangled\_qubits** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – If `True`, the rotation gates act only on qubits that are entangled. If `False`, the rotation gates act on all qubits. - **initial\_state** ([*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") *| None*) – A [`QuantumCircuit`](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") object which can be used to describe an initial state prepended to the NLocal circuit. - **name** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – The name of the circuit. - **flatten** ([*bool*](https://docs.python.org/3/library/functions.html#bool) *| None*) – Set this to `True` to output a flat circuit instead of nesting it inside multiple layers of gate objects. By default currently the contents of the output circuit will be wrapped in nested objects for cleaner visualization. However, if you’re using this circuit for anything besides visualization its **strongly** recommended to set this flag to `True` to avoid a large performance overhead for parameter binding. **Raises** - [**ValueError**](https://docs.python.org/3/library/exceptions.html#ValueError) – If `reps` parameter is less than or equal to 0. - [**TypeError**](https://docs.python.org/3/library/exceptions.html#TypeError) – If `reps` parameter is not an int value. ## Attributes ### ancillas A list of `AncillaQubit`s in the order that they were added. You should not mutate this. ### clbits A list of `Clbit`s in the order that they were added. You should not mutate this. **Example** ```python from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit qr1 = QuantumRegister(2) qr2 = QuantumRegister(1) cr1 = ClassicalRegister(2) cr2 = ClassicalRegister(1) qc = QuantumCircuit(qr1, qr2, cr1, cr2) print("List the qubits in this circuit:", qc.qubits) print("List the classical bits in this circuit:", qc.clbits) ``` ```text List the qubits in this circuit: [Qubit(QuantumRegister(2, 'q0'), 0), Qubit(QuantumRegister(2, 'q0'), 1), Qubit(QuantumRegister(1, 'q1'), 0)] List the classical bits in this circuit: [Clbit(ClassicalRegister(2, 'c0'), 0), Clbit(ClassicalRegister(2, 'c0'), 1), Clbit(ClassicalRegister(1, 'c1'), 0)] ``` ### cregs A list of `Clbit`s in the order that they were added. You should not mutate this. ### data The circuit data (instructions and context). **Returns** a list-like object containing the [`CircuitInstruction`](/docs/api/qiskit/2.0/qiskit.circuit.CircuitInstruction "qiskit.circuit.CircuitInstruction")s for each instruction. **Return type** QuantumCircuitData ### duration The total duration of the circuit, set by a scheduling transpiler pass. Its unit is specified by [`unit`](#qiskit.circuit.library.NLocal.unit "qiskit.circuit.library.NLocal.unit"). > **Deprecated since version 1.3.0** > > The property `qiskit.circuit.quantumcircuit.QuantumCircuit.duration` is deprecated as of Qiskit 1.3.0. It will be removed in Qiskit 3.0.0. ### entanglement Get the entanglement strategy. **Returns** The entanglement strategy, see [`get_entangler_map()`](#qiskit.circuit.library.NLocal.get_entangler_map "qiskit.circuit.library.NLocal.get_entangler_map") for more detail on how the format is interpreted. ### entanglement\_blocks The blocks in the entanglement layers. **Returns** The blocks in the entanglement layers. ### flatten Returns whether the circuit is wrapped in nested gates/instructions or flattened. ### global\_phase The global phase of the current circuit scope in radians. **Example** ```python from qiskit import QuantumCircuit circuit = QuantumCircuit(2) circuit.h(0) circuit.cx(0, 1) print(circuit.global_phase) ``` ```text 0.0 ``` ```python from numpy import pi circuit.global_phase = pi/4 print(circuit.global_phase) ``` ```text 0.7853981633974483 ``` ### initial\_state Return the initial state that is added in front of the n-local circuit. **Returns** The initial state. ### insert\_barriers If barriers are inserted in between the layers or not. **Returns** `True`, if barriers are inserted in between the layers, `False` if not. ### instances Default value: `327` ### layout Return any associated layout information about the circuit. This attribute contains an optional [`TranspileLayout`](/docs/api/qiskit/2.0/qiskit.transpiler.TranspileLayout "qiskit.transpiler.TranspileLayout") object. This is typically set on the output from [`transpile()`](/docs/api/qiskit/2.0/compiler#qiskit.compiler.transpile "qiskit.compiler.transpile") or [`PassManager.run()`](/docs/api/qiskit/2.0/qiskit.transpiler.PassManager#run "qiskit.transpiler.PassManager.run") to retain information about the permutations caused on the input circuit by transpilation. There are two types of permutations caused by the [`transpile()`](/docs/api/qiskit/2.0/compiler#qiskit.compiler.transpile "qiskit.compiler.transpile") function: an initial layout that permutes the qubits based on the selected physical qubits on the [`Target`](/docs/api/qiskit/2.0/qiskit.transpiler.Target "qiskit.transpiler.Target"), and a final layout, which is an output permutation caused by [`SwapGate`](/docs/api/qiskit/2.0/qiskit.circuit.library.SwapGate "qiskit.circuit.library.SwapGate")s inserted during routing. **Example** ```python from qiskit import QuantumCircuit from qiskit.providers.fake_provider import GenericBackendV2 from qiskit.transpiler import generate_preset_pass_manager # Create circuit to test transpiler on qc = QuantumCircuit(3, 3) qc.h(0) qc.cx(0, 1) qc.swap(1, 2) qc.cx(0, 1) # Add measurements to the circuit qc.measure([0, 1, 2], [0, 1, 2]) # Specify the QPU to target backend = GenericBackendV2(3) # Transpile the circuit pass_manager = generate_preset_pass_manager( optimization_level=1, backend=backend ) transpiled = pass_manager.run(qc) # Print the layout after transpilation print(transpiled.layout.routing_permutation()) ``` ```text [0, 1, 2] ``` ### metadata Arbitrary user-defined dictionary of metadata for the circuit. Qiskit will not examine the content of this mapping, but it will pass it through the transpiler and reattach it to the output, so you can track your own metadata. **Example** ```python from qiskit import QuantumCircuit qc = QuantumCircuit(2, 2, metadata={'experiment_type': 'Bell state experiment'}) print(qc.metadata) ``` ```text {'experiment_type': 'Bell state experiment'} ``` ### num\_ancillas Return the number of ancilla qubits. **Example** ```python from qiskit import QuantumCircuit, QuantumRegister, AncillaRegister # Create a 2-qubit quantum circuit reg = QuantumRegister(2) qc = QuantumCircuit(reg) # Create an ancilla register with 1 qubit anc = AncillaRegister(1) qc.add_register(anc) # Add the ancilla register to the circuit print("Number of ancilla qubits:", qc.num_ancillas) ``` ```text Number of ancilla qubits: 1 ``` ### num\_captured\_stretches The number of stretches in the circuit marked as captured from an enclosing scope. This is the length of the `iter_captured_stretches()` iterable. If this is non-zero, [`num_input_vars`](#qiskit.circuit.library.NLocal.num_input_vars "qiskit.circuit.library.NLocal.num_input_vars") must be zero. ### num\_captured\_vars The number of real-time classical variables in the circuit marked as captured from an enclosing scope. This is the length of the `iter_captured_vars()` iterable. If this is non-zero, [`num_input_vars`](#qiskit.circuit.library.NLocal.num_input_vars "qiskit.circuit.library.NLocal.num_input_vars") must be zero. ### num\_clbits Return number of classical bits. **Example** ```python from qiskit import QuantumCircuit # Create a new circuit with two qubits and one classical bit qc = QuantumCircuit(2, 1) print("Number of classical bits:", qc.num_clbits) ``` ```text Number of classical bits: 1 ``` ### num\_declared\_stretches The number of stretches in the circuit that are declared by this circuit scope, excluding captures. This is the length of the `iter_declared_stretches()` iterable. ### num\_declared\_vars The number of real-time classical variables in the circuit that are declared by this circuit scope, excluding inputs or captures. This is the length of the `iter_declared_vars()` iterable. ### num\_identifiers The number of real-time classical variables and stretches in the circuit. This is equal to [`num_vars()`](#qiskit.circuit.library.NLocal.num_vars "qiskit.circuit.library.NLocal.num_vars") + [`num_stretches()`](#qiskit.circuit.library.NLocal.num_stretches "qiskit.circuit.library.NLocal.num_stretches"). ### num\_input\_vars The number of real-time classical variables in the circuit marked as circuit inputs. This is the length of the `iter_input_vars()` iterable. If this is non-zero, [`num_captured_vars`](#qiskit.circuit.library.NLocal.num_captured_vars "qiskit.circuit.library.NLocal.num_captured_vars") must be zero. ### num\_layers Return the number of layers in the n-local circuit. **Returns** The number of layers in the circuit. ### num\_parameters The number of parameter objects in the circuit. ### num\_parameters\_settable The number of total parameters that can be set to distinct values. This does not change when the parameters are bound or exchanged for same parameters, and therefore is different from `num_parameters` which counts the number of unique [`Parameter`](/docs/api/qiskit/2.0/qiskit.circuit.Parameter "qiskit.circuit.Parameter") objects currently in the circuit. **Returns** The number of parameters originally available in the circuit. > **Note** > > This quantity does not require the circuit to be built yet. ### num\_qubits Returns the number of qubits in this circuit. **Returns** The number of qubits. ### num\_stretches The number of stretches in the circuit. This is the length of the `iter_stretches()` iterable. ### num\_vars The number of real-time classical variables in the circuit. This is the length of the `iter_vars()` iterable. ### op\_start\_times Return a list of operation start times. > **Note** > > This attribute computes the estimate starting time of the operations in the scheduled circuit and only works for simple circuits that have no control flow or other classical feed-forward operations. This attribute is enabled once one of scheduling analysis passes runs on the quantum circuit. **Example** ```python from qiskit import QuantumCircuit from qiskit.providers.fake_provider import GenericBackendV2 from qiskit.transpiler import generate_preset_pass_manager qc = QuantumCircuit(2) qc.h(0) qc.cx(0, 1) qc.measure_all() # Print the original circuit print("Original circuit:") print(qc) # Transpile the circuit with a specific basis gates list and print the resulting circuit backend = GenericBackendV2(2, basis_gates=['u1', 'u2', 'u3', 'cx']) pm = generate_preset_pass_manager( optimization_level=1, backend=backend, scheduling_method="alap" ) transpiled_qc = pm.run(qc) print("Transpiled circuit with basis gates ['u1', 'u2', 'u3', 'cx']:") print(transpiled_qc) # Print the start times of each instruction in the transpiled circuit print("Start times of instructions in the transpiled circuit:") for instruction, start_time in zip(transpiled_qc.data, transpiled_qc.op_start_times): print(f"{instruction.operation.name}: {start_time}") ``` ```text Original circuit: ┌───┐ ░ ┌─┐ q_0: ┤ H ├──■───░─┤M├─── └───┘┌─┴─┐ ░ └╥┘┌─┐ q_1: ─────┤ X ├─░──╫─┤M├ └───┘ ░ ║ └╥┘ meas: 2/══════════════╩══╩═ 0 1 Transpiled circuit with basis gates ['u1', 'u2', 'u3', 'cx']: ┌─────────┐ ░ ┌─────────────────┐┌─┐ q_0 -> 0 ───┤ U2(0,π) ├──────■───░─┤ Delay(1255[dt]) ├┤M├ ┌──┴─────────┴───┐┌─┴─┐ ░ └───────┬─┬───────┘└╥┘ q_1 -> 1 ┤ Delay(196[dt]) ├┤ X ├─░─────────┤M├─────────╫─ └────────────────┘└───┘ ░ └╥┘ ║ meas: 2/═══════════════════════════════════╩══════════╩═ 1 0 Start times of instructions in the transpiled circuit: u2: 0 delay: 0 cx: 196 barrier: 2098 delay: 2098 measure: 3353 measure: 2098 ``` **Returns** List of integers representing instruction estimated start times. The index corresponds to the index of instruction in `QuantumCircuit.data`. **Raises** [**AttributeError**](https://docs.python.org/3/library/exceptions.html#AttributeError) – When circuit is not scheduled. ### ordered\_parameters The parameters used in the underlying circuit. This includes float values and duplicates. **Examples** ```python >>> # prepare circuit ... >>> print(nlocal) ┌───────┐┌──────────┐┌──────────┐┌──────────┐ q_0: ┤ Ry(1) ├┤ Ry(θ[1]) ├┤ Ry(θ[1]) ├┤ Ry(θ[3]) ├ └───────┘└──────────┘└──────────┘└──────────┘ >>> nlocal.parameters {Parameter(θ[1]), Parameter(θ[3])} >>> nlocal.ordered_parameters [1, Parameter(θ[1]), Parameter(θ[1]), Parameter(θ[3])] ``` **Returns** The parameters objects used in the circuit. ### parameter\_bounds The parameter bounds for the unbound parameters in the circuit. **Returns** A list of pairs indicating the bounds, as (lower, upper). None indicates an unbounded parameter in the corresponding direction. If `None` is returned, problem is fully unbounded. ### parameters The parameters defined in the circuit. This attribute returns the [`Parameter`](/docs/api/qiskit/2.0/qiskit.circuit.Parameter "qiskit.circuit.Parameter") objects in the circuit sorted alphabetically. Note that parameters instantiated with a [`ParameterVector`](/docs/api/qiskit/2.0/qiskit.circuit.ParameterVector "qiskit.circuit.ParameterVector") are still sorted numerically. **Examples** The snippet below shows that insertion order of parameters does not matter. ```python >>> from qiskit.circuit import QuantumCircuit, Parameter >>> a, b, elephant = Parameter("a"), Parameter("b"), Parameter("elephant") >>> circuit = QuantumCircuit(1) >>> circuit.rx(b, 0) >>> circuit.rz(elephant, 0) >>> circuit.ry(a, 0) >>> circuit.parameters # sorted alphabetically! ParameterView([Parameter(a), Parameter(b), Parameter(elephant)]) ``` Bear in mind that alphabetical sorting might be unintuitive when it comes to numbers. The literal “10” comes before “2” in strict alphabetical sorting. ```python >>> from qiskit.circuit import QuantumCircuit, Parameter >>> angles = [Parameter("angle_1"), Parameter("angle_2"), Parameter("angle_10")] >>> circuit = QuantumCircuit(1) >>> circuit.u(*angles, 0) >>> circuit.draw() ┌─────────────────────────────┐ q: ┤ U(angle_1,angle_2,angle_10) ├ └─────────────────────────────┘ >>> circuit.parameters ParameterView([Parameter(angle_1), Parameter(angle_10), Parameter(angle_2)]) ``` To respect numerical sorting, a [`ParameterVector`](/docs/api/qiskit/2.0/qiskit.circuit.ParameterVector "qiskit.circuit.ParameterVector") can be used. ```python >>> from qiskit.circuit import QuantumCircuit, Parameter, ParameterVector >>> x = ParameterVector("x", 12) >>> circuit = QuantumCircuit(1) >>> for x_i in x: ... circuit.rx(x_i, 0) >>> circuit.parameters ParameterView([ ParameterVectorElement(x[0]), ParameterVectorElement(x[1]), ParameterVectorElement(x[2]), ParameterVectorElement(x[3]), ..., ParameterVectorElement(x[11]) ]) ``` **Returns** The sorted [`Parameter`](/docs/api/qiskit/2.0/qiskit.circuit.Parameter "qiskit.circuit.Parameter") objects in the circuit. ### preferred\_init\_points The initial points for the parameters. Can be stored as initial guess in optimization. **Returns** The initial values for the parameters, or None, if none have been set. ### prefix Default value: `'circuit'` ### qregs A list of the quantum registers associated with the circuit. ### qubits A list of `Qubit`s in the order that they were added. You should not mutate this. ### reps The number of times rotation and entanglement block are repeated. **Returns** The number of repetitions. ### rotation\_blocks The blocks in the rotation layers. **Returns** The blocks in the rotation layers. ### unit The unit that [`duration`](#qiskit.circuit.library.NLocal.duration "qiskit.circuit.library.NLocal.duration") is specified in. > **Deprecated since version 1.3.0** > > The property `qiskit.circuit.quantumcircuit.QuantumCircuit.unit` is deprecated as of Qiskit 1.3.0. It will be removed in Qiskit 3.0.0. ### name Type: `str` A human-readable name for the circuit. **Example** ```python from qiskit import QuantumCircuit qc = QuantumCircuit(2, 2, name="my_circuit") print(qc.name) ``` ```text my_circuit ``` ## Methods ### add\_layer `add_layer(other, entanglement=None, front=False)` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L985-L1045) Append another layer to the NLocal. **Parameters** - **other** ([*QuantumCircuit*](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") *|*[*qiskit.circuit.Instruction*](/docs/api/qiskit/2.0/qiskit.circuit.Instruction "qiskit.circuit.Instruction")) – The layer to compose, can be another NLocal, an Instruction or Gate, or a QuantumCircuit. - **entanglement** ([*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] |* [*str*](https://docs.python.org/3/library/stdtypes.html#str) *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*list*](https://docs.python.org/3/library/stdtypes.html#list)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*]] | None*) – The entanglement or qubit indices. - **front** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – If True, `other` is appended to the front, else to the back. **Returns** self, such that chained composes are possible. **Raises** [**TypeError**](https://docs.python.org/3/library/exceptions.html#TypeError) – If other is not compatible, i.e. is no Instruction and does not have a to\_instruction method. **Return type** [NLocal](#qiskit.circuit.library.NLocal "qiskit.circuit.library.NLocal") ### assign\_parameters `assign_parameters(parameters, inplace=False, **kwargs)` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L1047-L1075) Assign parameters to the n-local circuit. This method also supports passing a list instead of a dictionary. If a list is passed, the list must have the same length as the number of unbound parameters in the circuit. The parameters are assigned in the order of the parameters in [`ordered_parameters()`](#qiskit.circuit.library.NLocal.ordered_parameters "qiskit.circuit.library.NLocal.ordered_parameters"). **Returns** A copy of the NLocal circuit with the specified parameters. **Raises** [**AttributeError**](https://docs.python.org/3/library/exceptions.html#AttributeError) – If the parameters are given as list and do not match the number of parameters. **Parameters** - **parameters** (*Mapping\[*[*Parameter*](/docs/api/qiskit/2.0/qiskit.circuit.Parameter "qiskit.circuit.Parameter")*,* [*ParameterExpression*](/docs/api/qiskit/2.0/qiskit.circuit.ParameterExpression "qiskit.circuit.ParameterExpression") *|*[*float*](https://docs.python.org/3/library/functions.html#float)*] | Sequence\[*[*ParameterExpression*](/docs/api/qiskit/2.0/qiskit.circuit.ParameterExpression "qiskit.circuit.ParameterExpression") *|*[*float*](https://docs.python.org/3/library/functions.html#float)*]*) – - **inplace** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – **Return type** [QuantumCircuit](/docs/api/qiskit/2.0/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") | None ### get\_entangler\_map `get_entangler_map(rep_num, block_num, num_block_qubits)` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L818-L938) Get the entangler map for in the repetition `rep_num` and the block `block_num`. The entangler map for the current block is derived from the value of `self.entanglement`. Below the different cases are listed, where `i` and `j` denote the repetition number and the block number, respectively, and `n` the number of qubits in the block. | entanglement type | entangler map | | -------------------------------- | -------------------------------------------------- | | `None` | `[[0, ..., n - 1]]` | | `str` (e.g `'full'`) | the specified connectivity on `n` qubits | | `List[int]` | \[`entanglement`] | | `List[List[int]]` | `entanglement` | | `List[List[List[int]]]` | `entanglement[i]` | | `List[List[List[List[int]]]]` | `entanglement[i][j]` | | `List[str]` | the connectivity specified in `entanglement[i]` | | `List[List[str]]` | the connectivity specified in `entanglement[i][j]` | | `Callable[int, str]` | same as `List[str]` | | `Callable[int, List[List[int]]]` | same as `List[List[List[int]]]` | Note that all indices are to be taken modulo the length of the array they act on, i.e. no out-of-bounds index error will be raised but we re-iterate from the beginning of the list. **Parameters** - **rep\_num** ([*int*](https://docs.python.org/3/library/functions.html#int)) – The current repetition we are in. - **block\_num** ([*int*](https://docs.python.org/3/library/functions.html#int)) – The block number within the entanglement layers. - **num\_block\_qubits** ([*int*](https://docs.python.org/3/library/functions.html#int)) – The number of qubits in the block. **Returns** The entangler map for the current block in the current repetition. **Raises** [**ValueError**](https://docs.python.org/3/library/exceptions.html#ValueError) – If the value of `entanglement` could not be cast to a corresponding entangler map. **Return type** [*Sequence*](https://docs.python.org/3/library/collections.abc.html#collections.abc.Sequence)\[[*Sequence*](https://docs.python.org/3/library/collections.abc.html#collections.abc.Sequence)\[[int](https://docs.python.org/3/library/functions.html#int)]] ### get\_unentangled\_qubits `get_unentangled_qubits()` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L709-L722) Get the indices of unentangled qubits in a set. **Returns** The unentangled qubits. **Return type** [set](https://docs.python.org/3/library/stdtypes.html#set)\[[int](https://docs.python.org/3/library/functions.html#int)] ### print\_settings `print_settings()` [GitHub](https://github.com/Qiskit/qiskit/tree/stable/2.0/qiskit/circuit/library/n_local/n_local.py#L794-L806) Returns information about the setting. **Returns** The class name and the attributes/parameters of the instance as `str`. **Return type** [str](https://docs.python.org/3/library/stdtypes.html#str)