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IBMCircuitJob

IBMCircuitJob(backend, api_client, job_id, creation_date=None, status=None, runtime_client=None, kind=None, name=None, time_per_step=None, result=None, error=None, session_id=None, tags=None, run_mode=None, client_info=None, **kwargs) GitHub(opens in a new tab)

Representation of a job that executes on an IBM Quantum backend.

The job may be executed on a simulator or a real device. A new IBMCircuitJob instance is returned when you call IBMBackend.run() to submit a job to a particular backend.

If the job is successfully submitted, you can inspect the job’s status by calling status(). Job status can be one of the JobStatus members. For example:

from qiskit.providers.jobstatus import JobStatus
 
job = backend.run(...)
 
try:
    job_status = job.status()  # Query the backend server for job status.
    if job_status is JobStatus.RUNNING:
        print("The job is still running")
except IBMJobApiError as ex:
    print("Something wrong happened!: {}".format(ex))
Note

An error may occur when querying the remote server to get job information. The most common errors are temporary network failures and server errors, in which case an IBMJobApiError is raised. These errors usually clear quickly, so retrying the operation is likely to succeed.

Some of the methods in this class are blocking, which means control may not be returned immediately. result() is an example of a blocking method:

job = backend.run(...)
 
try:
    job_result = job.result()  # It will block until the job finishes.
    print("The job finished with result {}".format(job_result))
except JobError as ex:
    print("Something wrong happened!: {}".format(ex))

Job information retrieved from the server is attached to the IBMCircuitJob instance as attributes. Given that Qiskit and the server can be updated independently, some of these attributes might be deprecated or experimental. Supported attributes can be retrieved via methods. For example, you can use creation_date() to retrieve the job creation date, which is a supported attribute.

IBMCircuitJob constructor.

Parameters

  • backend (IBMBackend) – The backend instance used to run this job.
  • api_client (AccountClient) – Object for connecting to the server.
  • job_id (str) – Job ID.
  • creation_date (Optional[str]) – Job creation date.
  • status (Optional[str]) – Job status returned by the server.
  • runtime_client (Optional[RuntimeClient]) – Object for connecting to the runtime server
  • kind (Optional[str]) – Job type.
  • name (Optional[str]) – Job name.
  • time_per_step (Optional[dict]) – Time spent for each processing step.
  • result (Optional[dict]) – Job result.
  • error (Optional[dict]) – Job error.
  • tags (Optional[List[str]]) – Job tags.
  • run_mode (Optional[str]) – Scheduling mode the job runs in.
  • client_info (Optional[Dict[str, str]]) – Client information from the API.
  • kwargs (Any) – Additional job attributes.

Attributes

client_version

Return version of the client used for this job.

Return type

Dict[str, str]

Returns

Client version in dictionary format, where the key is the name

of the client and the value is the version.

usage_estimation

Return usage estimation information for this job.

Return type

Dict[str, Any]

Returns

quantum_seconds which is the estimated quantum time of the job in seconds. Quantum time represents the time that the QPU complex is occupied exclusively by the job.

version

= 1


Methods

backend

backend()

Return the backend where this job was executed.

Return type

Backend

backend_options

backend_options()

Return the backend configuration options used for this job.

Options that are not applicable to the job execution are not returned. Some but not all of the options with default values are returned. You can use qiskit_ibm_provider.IBMBackend.options to see all backend options.

Return type

Dict

Returns

Backend options used for this job. An empty dictionary is returned if the options cannot be retrieved.

cancel

cancel()

Attempt to cancel the job.

Note

Depending on the state the job is in, it might be impossible to cancel the job.

Return type

bool

Returns

True if the job is cancelled, else False.

Raises

cancelled

cancelled()

Return whether the job has been cancelled.

Return type

bool

circuits

circuits()

Return the circuits for this job.

Return type

List[QuantumCircuit]

Returns

The circuits or for this job. An empty list is returned if the circuits cannot be retrieved (for example, if the job uses an old format that is no longer supported).

creation_date

creation_date()

Return job creation date, in local time.

Return type

datetime

Returns

The job creation date as a datetime object, in local time.

done

done()

Return whether the job has successfully run.

Return type

bool

error_message

error_message()

Provide details about the reason of failure.

Return type

Optional[str]

Returns

An error report if the job failed or None otherwise.

header()

Return the user header specified for this job.

Return type

Dict

Returns

User header specified for this job. An empty dictionary is returned if the header cannot be retrieved.

in_final_state

in_final_state()

Return whether the job is in a final job state such as DONE or ERROR.

Return type

bool

job_id

job_id()

Return the job ID assigned by the server.

Return type

str

Returns

Job ID.

name

name()

Return the name assigned to this job.

Return type

Optional[str]

Returns

Job name or None if no name was assigned to this job.

properties

properties(refresh=False)

Return the backend properties for this job.

Parameters

refresh (bool) – If True, re-query the server for the backend properties. Otherwise, return a cached version.

Return type

Optional[BackendProperties]

Returns

The backend properties used for this job, at the time the job was run, or None if properties are not available.

queue_info

queue_info()

Return queue information for this job.

The queue information may include queue position, estimated start and end time, and dynamic priorities for the hub, group, and project. See QueueInfo for more information.

Note

The queue information is calculated after the job enters the queue. Therefore, some or all of the information may not be immediately available, and this method may return None.

Return type

Optional[QueueInfo]

Returns

A QueueInfo instance that contains queue information for this job, or None if queue information is unknown or not applicable.

queue_position

queue_position(refresh=False)

Return the position of the job in the server queue.

Note

The position returned is within the scope of the provider and may differ from the global queue position.

Parameters

refresh (bool) – If True, re-query the server to get the latest value. Otherwise return the cached value.

Return type

Optional[int]

Returns

Position in the queue or None if position is unknown or not applicable.

refresh

refresh()

Obtain the latest job information from the server.

This method may add additional attributes to this job instance, if new information becomes available.

Raises

IBMJobApiError – If an unexpected error occurred when communicating with the server.

Return type

None

result

result(timeout=None, refresh=False)

Return the result of the job.

Note

Some IBM Quantum job results can only be read once. A second attempt to query the server for the same job will fail, since the job has already been “consumed”.

The first call to this method in an IBMCircuitJob instance will query the server and consume any available job results. Subsequent calls to that instance’s result() will also return the results, since they are cached. However, attempting to retrieve the results again in another instance or session might fail due to the job results having been consumed.

Note

When partial=True, this method will attempt to retrieve partial results of failed jobs. In this case, precaution should be taken when accessing individual experiments, as doing so might cause an exception. The success attribute of the returned Result instance can be used to verify whether it contains partial results.

For example, if one of the experiments in the job failed, trying to get the counts of the unsuccessful experiment would raise an exception since there are no counts to return:

try:
    counts = result.get_counts("failed_experiment")
except QiskitError:
    print("Experiment failed!")

If the job failed, you can use error_message() to get more information.

Parameters

  • timeout (Optional[float]) – Number of seconds to wait for job.
  • refresh (bool) – If True, re-query the server for the result. Otherwise return the cached value.

Return type

Result

Returns

Job result.

Raises

running

running()

Return whether the job is actively running.

Return type

bool

scheduling_mode

scheduling_mode()

Return the scheduling mode the job is in.

Return type

Optional[str]

Returns

The scheduling mode the job is in or None if the information is not available.

status

status()

Query the server for the latest job status.

Note

This method is not designed to be invoked repeatedly in a loop for an extended period of time. Doing so may cause the server to reject your request. Use wait_for_final_state() if you want to wait for the job to finish.

Note

If the job failed, you can use error_message() to get more information.

Return type

JobStatus

Returns

The status of the job.

Raises

IBMJobApiError – If an unexpected error occurred when communicating with the server.

submit

submit()

Unsupported method.

Note

This method is not supported, please use run() to submit a job.

Raises

NotImplementedError – Upon invocation.

Return type

None

tags

tags()

Return the tags assigned to this job.

Return type

List[str]

Returns

Tags assigned to this job.

time_per_step

time_per_step()

Return the date and time information on each step of the job processing.

The output dictionary contains the date and time information on each step of the job processing, in local time. The keys of the dictionary are the names of the steps, and the values are the date and time data, as a datetime object with local timezone info. For example:

{'CREATING': datetime(2020, 2, 13, 15, 19, 25, 717000, tzinfo=tzlocal(),
 'CREATED': datetime(2020, 2, 13, 15, 19, 26, 467000, tzinfo=tzlocal(),
 'VALIDATING': datetime(2020, 2, 13, 15, 19, 26, 527000, tzinfo=tzlocal()}

Return type

Optional[Dict]

Returns

Date and time information on job processing steps, in local time, or None if the information is not yet available.

update_name

update_name(name)

Update the name associated with this job.

Parameters

name (str) – The new name for this job.

Return type

str

Returns

The new name associated with this job.

update_tags

update_tags(new_tags)

Update the tags associated with this job.

Parameters

new_tags (List[str]) – New tags to assign to the job.

Return type

List[str]

Returns

The new tags associated with this job.

Raises

  • IBMJobApiError – If an unexpected error occurred when communicating with the server or updating the job tags.
  • IBMJobInvalidStateError – If none of the input parameters are specified or if any of the input parameters are invalid.

wait_for_final_state

wait_for_final_state(timeout=None, wait=3)

Use the websocket server to wait for the final the state of a job. The server

will remain open if the job is still running and the connection will be terminated once the job completes. Then update and return the status of the job.

Parameters

timeout (Optional[float]) – Seconds to wait for the job. If None, wait indefinitely.

Raises

IBMJobTimeoutError – If the job does not complete within given timeout.

Return type

None

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