qrunch.quantum.backends.backends_protocols

Protocols used for backends.

Classes

`Backend`	Class for handling backends.
`BackendJob`	Job class for handling quantum jobs, both quantum and simulated.
`BackendJobStatus`	Class with all possible job statuses.
`BackendResult`	Class for backend results.
`SimulatedJob`	Job class for handling simulated jobs using Qiskit.

class Backend

Bases: Protocol

Class for handling backends.

__init__(*args, **kwargs)

property name: str: Return the name of the backend.

run(circuits: Circuit | Sequence[Circuit], shots: int | None) → BackendJob

Run circuit on the backend.

Parameters:

circuits (Circuit | Sequence[Circuit]) – circuit to run on backend
shots (int | None) – number of shots

Return type:

BackendJob

Returns: A backend job which can fetch the result when done.

supports_shots_equals_none() → bool

Return whether the backend supports shots = None.

Shots = None means that a full state vector simulation is done.

Return type:: bool

class BackendJob

Bases: ABC

Job class for handling quantum jobs, both quantum and simulated.

abstract property backend: Backend: Backend used to calculate the job on.

abstractmethod cancel() → None

Cancel the job.

Return type:: None

abstract property job_id: str: ID of the job.

abstractmethod result() → BackendResult

Return the results of the job.

Return type:: BackendResult

abstractmethod status() → BackendJobStatus

Return the status of the job.

Return type:: BackendJobStatus

wait_for_final_state(timeout: float | None = None) → None

Wait until the job status is in a final state, i.e., DONE, CANCELLED, or FAILED.

Parameters:: timeout (float | None) – Seconds to wait for the job. If None, wait forever.
Raises:: TimeoutError – If the job does not reach a final state before the specified timeout.
Return type:: None

class BackendJobStatus

Bases: Enum

Class with all possible job statuses.

CANCELLED = 'job is cancelled'

DONE = 'job has run successfully'

FAILED = 'job has failed'

QUEUED = 'job is queued'

RUNNING = 'job is running'

done() → bool

Return True if the status is DONE.

Return type:: bool

is_final_state() → bool

Return whether the status is in a final state, i.e., DONE, CANCELLED, or FAILED.

Return type:: bool

is_queuing() → bool

Return whether the status is QUEUED.

Return type:: bool

class BackendResult

Bases: object

Class for backend results.

__init__(backend_name: str, job_id: str, measurements: Sequence[QuantumMeasurement], success: bool, exception: Exception | None = None) → None

Parameters:

backend_name (str)
job_id (str)
measurements (Sequence[QuantumMeasurement])
success (bool)
exception (Exception | None)

Return type:

None

backend_name: str: name of the backend

exception: Exception | None = None

job_id: str: identifier for the job

measurements: Sequence[QuantumMeasurement]: sequence of measurements

success: bool: True if the task is successful

class SimulatedJob

Bases: BackendJob

Job class for handling simulated jobs using Qiskit.

__init__(backend: Backend, job_id: str, result: BackendResult) → None

Initialize a simulated job.

Parameters:

backend (Backend) – Backend used for the job
job_id (str) – id of the job as a string
result (BackendResult) – Result of the job.

Return type:

None

property backend: Backend: Backend used for the job.

cancel() → None

Just a simulated job, so nothing to cancel.

Return type:: None

property job_id: str: ID of the job.

result() → BackendResult

Get the results of the simulation.

Return type:: BackendResult

status() → BackendJobStatus

Return the status of the job.

Return type:: BackendJobStatus

wait_for_final_state(timeout: float | None = None) → None

Wait until the job status is in a final state, i.e., DONE, CANCELLED, or FAILED.

Parameters:: timeout (float | None) – Seconds to wait for the job. If None, wait forever.
Raises:: TimeoutError – If the job does not reach a final state before the specified timeout.
Return type:: None