---
title: compiler (v0.46)
description: API reference for qiskit.compiler in qiskit v0.46
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/0.46/compiler
---

# Compilation Routines

`qiskit.compiler`

## Circuit and Pulse Compilation Functions

### assemble

`qiskit.compiler.assemble(experiments, backend=None, qobj_id=None, qobj_header=None, shots=None, memory=False, seed_simulator=None, qubit_lo_freq=None, meas_lo_freq=None, qubit_lo_range=None, meas_lo_range=None, schedule_los=None, meas_level=MeasLevel.CLASSIFIED, meas_return=MeasReturnType.AVERAGE, meas_map=None, memory_slot_size=100, rep_time=None, rep_delay=None, parameter_binds=None, parametric_pulses=None, init_qubits=True, **run_config)`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/compiler/assembler.py)

Assemble a list of circuits or pulse schedules into a `Qobj`.

This function serializes the payloads, which could be either circuits or schedules, to create `Qobj` “experiments”. It further annotates the experiment payload with header and configurations.

NOTE: Backend.options is not used within assemble. The required values (previously given by backend.set\_options) should be manually extracted from options and supplied directly when calling.

**Parameters**

- **experiments** ([*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")*] |* [*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule")*] |* [*ScheduleBlock*](/docs/api/qiskit/0.46/qiskit.pulse.ScheduleBlock "qiskit.pulse.schedule.ScheduleBlock")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*ScheduleBlock*](/docs/api/qiskit/0.46/qiskit.pulse.ScheduleBlock "qiskit.pulse.schedule.ScheduleBlock")*]*) – Circuit(s) or pulse schedule(s) to execute

- **backend** ([*Backend*](/docs/api/qiskit/0.46/qiskit.providers.Backend "qiskit.providers.backend.Backend") *| None*) – If set, some runtime options are automatically grabbed from `backend.configuration()` and `backend.defaults()`. If any other option is explicitly set (e.g., `rep_time`), it will override the backend’s. If any other options is set in the run\_config, it will also override the backend’s.

- **qobj\_id** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – String identifier to annotate the `Qobj`

- **qobj\_header** ([*QobjHeader*](/docs/api/qiskit/0.46/qiskit.qobj.QobjHeader "qiskit.qobj.common.QobjHeader")  *|*[*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict) *| None*) – User input that will be inserted in `Qobj` header, and will also be copied to the corresponding Result header. Headers do not affect the run.

- **shots** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) – Number of repetitions of each circuit, for sampling. Default: 1024 or `max_shots` from the backend configuration, whichever is smaller

- **memory** ([*bool*](https://docs.python.org/3/library/functions.html#bool) *| None*) – If `True`, per-shot measurement bitstrings are returned as well (provided the backend supports it). For OpenPulse jobs, only measurement level 2 supports this option.

- **seed\_simulator** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) – Random seed to control sampling, for when backend is a simulator

- **qubit\_lo\_freq** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None*) – List of job level qubit drive LO frequencies in Hz. Overridden by `schedule_los` if specified. Must have length `n_qubits.`

- **meas\_lo\_freq** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None*) – List of measurement LO frequencies in Hz. Overridden by `schedule_los` if specified. Must have length `n_qubits.`

- **qubit\_lo\_range** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None*) – List of job level drive LO ranges each of form `[range_min, range_max]` in Hz. Used to validate `qubit_lo_freq`. Must have length `n_qubits.`

- **meas\_lo\_range** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None*) – List of job level measurement LO ranges each of form `[range_min, range_max]` in Hz. Used to validate `meas_lo_freq`. Must have length `n_qubits.`

- **schedule\_los** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)*\[PulseChannel,* [*float*](https://docs.python.org/3/library/functions.html#float)*] | LoConfig] |* [*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)*\[PulseChannel,* [*float*](https://docs.python.org/3/library/functions.html#float)*] | LoConfig | None*) – Experiment level (ie circuit or schedule) LO frequency configurations for qubit drive and measurement channels. These values override the job level values from `default_qubit_los` and `default_meas_los`. Frequencies are in Hz. Settable for OpenQASM 2 and pulse jobs.

- **meas\_level** ([*int*](https://docs.python.org/3/library/functions.html#int) *| MeasLevel*) – Set the appropriate level of the measurement output for pulse experiments.

- **meas\_return** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| MeasReturnType*) –

  Level of measurement data for the backend to return.

  **For `meas_level` 0 and 1:**

  - `single` returns information from every shot.
  - `avg` returns average measurement output (averaged over number of shots).

- **meas\_map** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Qubit*](/docs/api/qiskit/0.46/qiskit.circuit.Qubit "qiskit.circuit.quantumregister.Qubit")*]] | None*) – List of lists, containing qubits that must be measured together.

- **memory\_slot\_size** ([*int*](https://docs.python.org/3/library/functions.html#int)) – Size of each memory slot if the output is Level 0.

- **rep\_time** ([*int*](https://docs.python.org/3/library/functions.html#int)) – Time per program execution in seconds. Must be from the list provided by the backend (`backend.configuration().rep_times`). Defaults to the first entry.

- **rep\_delay** ([*float*](https://docs.python.org/3/library/functions.html#float)) – Delay between programs in seconds. Only supported on certain backends (if `backend.configuration().dynamic_reprate_enabled=True`). If supported, `rep_delay` will be used instead of `rep_time` and must be from the range supplied by the backend (`backend.configuration().rep_delay_range`). Default is given by `backend.configuration().default_rep_delay`.

- **parameter\_binds** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)*\[*[*Parameter*](/docs/api/qiskit/0.46/qiskit.circuit.Parameter "qiskit.circuit.parameter.Parameter")*,* [*float*](https://docs.python.org/3/library/functions.html#float)*]] | None*) – List of Parameter bindings over which the set of experiments will be executed. Each list element (bind) should be of the form \{Parameter1: value1, Parameter2: value2, …}. All binds will be executed across all experiments; e.g., if parameter\_binds is a length-n list, and there are m experiments, a total of m x n experiments will be run (one for each experiment/bind pair).

- **parametric\_pulses** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*] | None*) –

  A list of pulse shapes which are supported internally on the backend. Example:

  ```python
  ['gaussian', 'constant']
  ```

- **init\_qubits** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – Whether to reset the qubits to the ground state for each shot. Default: `True`.

- **\*\*run\_config** ([*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)) – Extra arguments used to configure the run (e.g., for Aer configurable backends). Refer to the backend documentation for details on these arguments.

**Returns**

A `Qobj` that can be run on a backend. Depending on the type of input, this will be either a `QasmQobj` or a `PulseQobj`.

**Raises**

[**QiskitError**](/docs/api/qiskit/0.46/exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") – if the input cannot be interpreted as either circuits or schedules

**Return type**

[*QasmQobj*](/docs/api/qiskit/0.46/qiskit.qobj.QasmQobj "qiskit.qobj.qasm_qobj.QasmQobj") | [*PulseQobj*](/docs/api/qiskit/0.46/qiskit.qobj.PulseQobj "qiskit.qobj.pulse_qobj.PulseQobj")

### schedule

`qiskit.compiler.schedule(circuits, backend=None, inst_map=None, meas_map=None, dt=None, method=None)`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/compiler/scheduler.py)

Schedule a circuit to a pulse `Schedule`, using the backend, according to any specified methods. Supported methods are documented in `qiskit.scheduler.schedule_circuit`.

**Parameters**

- **circuits** ([*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")*]*) – The quantum circuit or circuits to translate
- **backend** ([*Backend*](/docs/api/qiskit/0.46/qiskit.providers.Backend "qiskit.providers.backend.Backend") *| None*) – A backend instance, which contains hardware-specific data required for scheduling
- **inst\_map** ([*InstructionScheduleMap*](/docs/api/qiskit/0.46/qiskit.pulse.InstructionScheduleMap "qiskit.pulse.instruction_schedule_map.InstructionScheduleMap") *| None*) – Mapping of circuit operations to pulse schedules. If `None`, defaults to the `backend`’s `instruction_schedule_map`
- **meas\_map** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*]] | None*) – List of sets of qubits that must be measured together. If `None`, defaults to the `backend`’s `meas_map`
- **dt** ([*float*](https://docs.python.org/3/library/functions.html#float) *| None*) – The output sample rate of backend control electronics. For scheduled circuits which contain time information, dt is required. If not provided, it will be obtained from the backend configuration
- **method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*] | None*) – Optionally specify a particular scheduling method

**Returns**

A pulse `Schedule` that implements the input circuit

**Raises**

[**QiskitError**](/docs/api/qiskit/0.46/exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") – If `inst_map` and `meas_map` are not passed and `backend` is not passed

**Return type**

[*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule") | [*List*](https://docs.python.org/3/library/typing.html#typing.List)\[[*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule")]

### transpile

`qiskit.compiler.transpile(circuits, backend=None, basis_gates=None, inst_map=None, coupling_map=None, backend_properties=None, initial_layout=None, layout_method=None, routing_method=None, translation_method=None, scheduling_method=None, instruction_durations=None, dt=None, approximation_degree=1.0, timing_constraints=None, seed_transpiler=None, optimization_level=None, callback=None, output_name=None, unitary_synthesis_method='default', unitary_synthesis_plugin_config=None, target=None, hls_config=None, init_method=None, optimization_method=None, ignore_backend_supplied_default_methods=False)`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/compiler/transpiler.py)

Transpile one or more circuits, according to some desired transpilation targets.

Transpilation is potentially done in parallel using multiprocessing when `circuits` is a list with > 1 [`QuantumCircuit`](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.QuantumCircuit") object depending on the local environment and configuration.

**Parameters**

- **circuits** (*\_CircuitT*) – Circuit(s) to transpile

- **backend** ([*Backend*](/docs/api/qiskit/0.46/qiskit.providers.Backend "qiskit.providers.backend.Backend") *| None*) – If set, the transpiler will compile the input circuit to this target device. If any other option is explicitly set (e.g., `coupling_map`), it will override the backend’s.

- **basis\_gates** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*] | None*) – List of basis gate names to unroll to (e.g: `['u1', 'u2', 'u3', 'cx']`). If `None`, do not unroll.

- **inst\_map** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*InstructionScheduleMap*](/docs/api/qiskit/0.46/qiskit.pulse.InstructionScheduleMap "qiskit.pulse.instruction_schedule_map.InstructionScheduleMap")*] | None*) – Mapping of unrolled gates to pulse schedules. If this is not provided, transpiler tries to get from the backend. If any user defined calibration is found in the map and this is used in a circuit, transpiler attaches the custom gate definition to the circuit. This enables one to flexibly override the low-level instruction implementation. This feature is available iff the backend supports the pulse gate experiment.

- **coupling\_map** ([*CouplingMap*](/docs/api/qiskit/0.46/qiskit.transpiler.CouplingMap "qiskit.transpiler.coupling.CouplingMap")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*]] | None*) –

  Directed coupling map (perhaps custom) to target in mapping. If the coupling map is symmetric, both directions need to be specified.

  Multiple formats are supported:

  1. `CouplingMap` instance
  2. List, must be given as an adjacency matrix, where each entry specifies all directed two-qubit interactions supported by backend, e.g: `[[0, 1], [0, 3], [1, 2], [1, 5], [2, 5], [4, 1], [5, 3]]`

- **backend\_properties** ([*BackendProperties*](/docs/api/qiskit/0.46/qiskit.providers.models.BackendProperties "qiskit.providers.models.backendproperties.BackendProperties") *| None*) – properties returned by a backend, including information on gate errors, readout errors, qubit coherence times, etc. Find a backend that provides this information with: `backend.properties()`

- **initial\_layout** ([*Layout*](/docs/api/qiskit/0.46/qiskit.transpiler.Layout "qiskit.transpiler.layout.Layout")  *|*[*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List) *| None*) –

  Initial position of virtual qubits on physical qubits. If this layout makes the circuit compatible with the coupling\_map constraints, it will be used. The final layout is not guaranteed to be the same, as the transpiler may permute qubits through swaps or other means. Multiple formats are supported:

  1. `Layout` instance

  2. Dict \* virtual to physical:

     ```python
     {qr[0]: 0,
      qr[1]: 3,
      qr[2]: 5}
     ```

     - physical to virtual:

       ```python
       {0: qr[0],
        3: qr[1],
        5: qr[2]}
       ```

  3. List

     - virtual to physical:

       ```python
       [0, 3, 5]  # virtual qubits are ordered (in addition to named)
       ```

     - physical to virtual:

       ```python
       [qr[0], None, None, qr[1], None, qr[2]]
       ```

- **layout\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – Name of layout selection pass (‘trivial’, ‘dense’, ‘noise\_adaptive’, ‘sabre’). This can also be the external plugin name to use for the `layout` stage. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"layout"` for the `stage_name` argument.

- **routing\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – Name of routing pass (‘basic’, ‘lookahead’, ‘stochastic’, ‘sabre’, ‘none’). Note This can also be the external plugin name to use for the `routing` stage. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"routing"` for the `stage_name` argument.

- **translation\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – Name of translation pass (‘unroller’, ‘translator’, ‘synthesis’) This can also be the external plugin name to use for the `translation` stage. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"translation"` for the `stage_name` argument.

- **scheduling\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – Name of scheduling pass. \* `'as_soon_as_possible'`: Schedule instructions greedily, as early as possible on a qubit resource. (alias: `'asap'`) \* `'as_late_as_possible'`: Schedule instructions late, i.e. keeping qubits in the ground state when possible. (alias: `'alap'`) If `None`, no scheduling will be done. This can also be the external plugin name to use for the `scheduling` stage. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"scheduling"` for the `stage_name` argument.

- **instruction\_durations** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] | None,* [*float*](https://docs.python.org/3/library/functions.html#float)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None,* [*str*](https://docs.python.org/3/library/stdtypes.html#str)*]] |* [*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] | None,* [*float*](https://docs.python.org/3/library/functions.html#float)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*float*](https://docs.python.org/3/library/functions.html#float)*] | None]] |* [*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] | None,* [*float*](https://docs.python.org/3/library/functions.html#float)*,* [*str*](https://docs.python.org/3/library/stdtypes.html#str)*]] |* [*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*,* [*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*] | None,* [*float*](https://docs.python.org/3/library/functions.html#float)*]] |* [*InstructionDurations*](/docs/api/qiskit/0.46/qiskit.transpiler.InstructionDurations "qiskit.transpiler.instruction_durations.InstructionDurations") *| None*) – Durations of instructions. Applicable only if scheduling\_method is specified. The gate lengths defined in `backend.properties` are used as default. They are overwritten if this `instruction_durations` is specified. The format of `instruction_durations` must be as follows. The instruction\_durations must be given as a list of tuples \[(instruction\_name, qubits, duration, unit), …]. | \[(‘cx’, \[0, 1], 12.3, ‘ns’), (‘u3’, \[0], 4.56, ‘ns’)] | \[(‘cx’, \[0, 1], 1000), (‘u3’, \[0], 300)] If unit is omitted, the default is ‘dt’, which is a sample time depending on backend. If the time unit is ‘dt’, the duration must be an integer.

- **dt** ([*float*](https://docs.python.org/3/library/functions.html#float) *| None*) – Backend sample time (resolution) in seconds. If `None` (default), `backend.configuration().dt` is used.

- **approximation\_degree** ([*float*](https://docs.python.org/3/library/functions.html#float)) – heuristic dial used for circuit approximation (1.0=no approximation, 0.0=maximal approximation)

- **timing\_constraints** ([*Dict*](https://docs.python.org/3/library/typing.html#typing.Dict)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*,* [*int*](https://docs.python.org/3/library/functions.html#int)*] | None*) –

  An optional control hardware restriction on instruction time resolution. A quantum computer backend may report a set of restrictions, namely:

  - granularity: An integer value representing minimum pulse gate resolution in units of `dt`. A user-defined pulse gate should have duration of a multiple of this granularity value.
  - min\_length: An integer value representing minimum pulse gate length in units of `dt`. A user-defined pulse gate should be longer than this length.
  - pulse\_alignment: An integer value representing a time resolution of gate instruction starting time. Gate instruction should start at time which is a multiple of the alignment value.
  - acquire\_alignment: An integer value representing a time resolution of measure instruction starting time. Measure instruction should start at time which is a multiple of the alignment value.

  This information will be provided by the backend configuration. If the backend doesn’t have any restriction on the instruction time allocation, then `timing_constraints` is None and no adjustment will be performed.

- **seed\_transpiler** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) – Sets random seed for the stochastic parts of the transpiler

- **optimization\_level** ([*int*](https://docs.python.org/3/library/functions.html#int) *| None*) –

  How much optimization to perform on the circuits. Higher levels generate more optimized circuits, at the expense of longer transpilation time.

  - 0: no optimization
  - 1: light optimization
  - 2: heavy optimization
  - 3: even heavier optimization

  If `None`, level 1 will be chosen as default.

- **callback** ([*Callable*](https://docs.python.org/3/library/typing.html#typing.Callable)*\[\[BasePass,* [*DAGCircuit*](/docs/api/qiskit/0.46/qiskit.dagcircuit.DAGCircuit "qiskit.dagcircuit.dagcircuit.DAGCircuit")*,* [*float*](https://docs.python.org/3/library/functions.html#float)*,* [*PropertySet*](/docs/api/qiskit/0.46/qiskit.passmanager.PropertySet "qiskit.passmanager.compilation_status.PropertySet")*,* [*int*](https://docs.python.org/3/library/functions.html#int)*],* [*Any*](https://docs.python.org/3/library/typing.html#typing.Any)*] | None*) –

  A callback function that will be called after each pass execution. The function will be called with 5 keyword arguments, | `pass_`: the pass being run. | `dag`: the dag output of the pass. | `time`: the time to execute the pass. | `property_set`: the property set. | `count`: the index for the pass execution. The exact arguments passed expose the internals of the pass manager, and are subject to change as the pass manager internals change. If you intend to reuse a callback function over multiple releases, be sure to check that the arguments being passed are the same. To use the callback feature, define a function that will take in kwargs dict and access the variables. For example:

  ```python
  def callback_func(**kwargs):
      pass_ = kwargs['pass_']
      dag = kwargs['dag']
      time = kwargs['time']
      property_set = kwargs['property_set']
      count = kwargs['count']
      ...
  transpile(circ, callback=callback_func)
  ```

- **output\_name** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str)*] | None*) – A list with strings to identify the output circuits. The length of the list should be exactly the length of the `circuits` parameter.

- **unitary\_synthesis\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str)) – The name of the unitary synthesis method to use. By default `'default'` is used. You can see a list of installed plugins with [`unitary_synthesis_plugin_names()`](/docs/api/qiskit/0.46/qiskit.transpiler.passes.synthesis.plugin.unitary_synthesis_plugin_names "qiskit.transpiler.passes.synthesis.plugin.unitary_synthesis_plugin_names").

- **unitary\_synthesis\_plugin\_config** ([*dict*](https://docs.python.org/3/library/stdtypes.html#dict) *| None*) – An optional configuration dictionary that will be passed directly to the unitary synthesis plugin. By default this setting will have no effect as the default unitary synthesis method does not take custom configuration. This should only be necessary when a unitary synthesis plugin is specified with the `unitary_synthesis_method` argument. As this is custom for each unitary synthesis plugin refer to the plugin documentation for how to use this option.

- **target** ([*Target*](/docs/api/qiskit/0.46/qiskit.transpiler.Target "qiskit.transpiler.target.Target") *| None*) – A backend transpiler target. Normally this is specified as part of the `backend` argument, but if you have manually constructed a [`Target`](/docs/api/qiskit/0.46/qiskit.transpiler.Target "qiskit.transpiler.Target") object you can specify it manually here. This will override the target from `backend`.

- **hls\_config** (*HLSConfig | None*) – An optional configuration class `HLSConfig` that will be passed directly to `HighLevelSynthesis` transformation pass. This configuration class allows to specify for various high-level objects the lists of synthesis algorithms and their parameters.

- **init\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – The plugin name to use for the `init` stage. By default an external plugin is not used. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"init"` for the stage name argument.

- **optimization\_method** ([*str*](https://docs.python.org/3/library/stdtypes.html#str) *| None*) – The plugin name to use for the `optimization` stage. By default an external plugin is not used. You can see a list of installed plugins by using [`list_stage_plugins()`](/docs/api/qiskit/0.46/transpiler_plugins#qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins "qiskit.transpiler.preset_passmanagers.plugin.list_stage_plugins") with `"optimization"` for the `stage_name` argument.

- **ignore\_backend\_supplied\_default\_methods** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – If set to `True` any default methods specified by a backend will be ignored. Some backends specify alternative default methods to support custom compilation target-specific passes/plugins which support backend-specific compilation techniques. If you’d prefer that these defaults were not used this option is used to disable those backend-specific defaults.

**Returns**

The transpiled circuit(s).

**Raises**

[**TranspilerError**](/docs/api/qiskit/0.46/transpiler#qiskit.transpiler.TranspilerError "qiskit.transpiler.TranspilerError") – in case of bad inputs to transpiler (like conflicting parameters) or errors in passes

**Return type**

*\_CircuitT*

### sequence

`qiskit.compiler.sequence(scheduled_circuits, backend=None, inst_map=None, meas_map=None, dt=None)`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/compiler/sequencer.py)

Schedule a scheduled circuit to a pulse `Schedule`, using the backend.

**Parameters**

- **scheduled\_circuits** ([*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*QuantumCircuit*](/docs/api/qiskit/0.46/qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")*]*) – Scheduled circuit(s) to be translated
- **backend** ([*Backend*](/docs/api/qiskit/0.46/qiskit.providers.Backend "qiskit.providers.backend.Backend") *| None*) – A backend instance, which contains hardware-specific data required for scheduling
- **inst\_map** ([*InstructionScheduleMap*](/docs/api/qiskit/0.46/qiskit.pulse.InstructionScheduleMap "qiskit.pulse.instruction_schedule_map.InstructionScheduleMap") *| None*) – Mapping of circuit operations to pulse schedules. If `None`, defaults to the `backend`’s `instruction_schedule_map`
- **meas\_map** ([*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*int*](https://docs.python.org/3/library/functions.html#int)*]] | None*) – List of sets of qubits that must be measured together. If `None`, defaults to the `backend`’s `meas_map`
- **dt** ([*float*](https://docs.python.org/3/library/functions.html#float) *| None*) – The output sample rate of backend control electronics. For scheduled circuits which contain time information, dt is required. If not provided, it will be obtained from the backend configuration

**Returns**

A pulse `Schedule` that implements the input circuit

**Raises**

[**QiskitError**](/docs/api/qiskit/0.46/exceptions#qiskit.exceptions.QiskitError "qiskit.exceptions.QiskitError") – If `inst_map` and `meas_map` are not passed and `backend` is not passed

**Return type**

[*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule") | [*List*](https://docs.python.org/3/library/typing.html#typing.List)\[[*Schedule*](/docs/api/qiskit/0.46/qiskit.pulse.Schedule "qiskit.pulse.schedule.Schedule")]