IBMQJob

class IBMQJob(backend, api_client, job_id, creation_date, status, kind=None, name=None, time_per_step=None, result=None, qobj=None, error=None, tags=None, run_mode=None, share_level=None, client_info=None, experiment_id=None, **kwargs)

GitHub

Bases: qiskit.providers.job.JobV1

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

The job may be executed on a simulator or a real device. A new IBMQJob instance is returned when you call IBMQBackend.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 IBMQJobApiError 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 IBMQJobApiError 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 IBMQJob 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.

IBMQJob constructor.

Parameters

backend (IBMQBackend) – The backend instance used to run this job.
api_client (AccountClient) – Object for connecting to the server.
job_id (str) – Job ID.
creation_date (str) – Job creation date.
status (str) – Job status returned by the 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.
qobj (Union[dict, QasmQobj, PulseQobj, None]) – Qobj for this job.
error (Optional[dict]) – Job error.
tags (Optional[List[str]]) – Job tags.
run_mode (Optional[str]) – Scheduling mode the job runs in.
share_level (Optional[str]) – Level the job can be shared with.
client_info (Optional[Dict[str, str]]) – Client version.
experiment_id (Optional[str]) – ID of the experiment this job is part of.
kwargs (Any) – Additional job attributes.

Methods

backend

IBMQJob.backend()

Return the backend where this job was executed.

Return type

Backend

backend_options

IBMQJob.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.providers.ibmq.IBMQBackend.options to see all backend options.

Return type

Dict[str, Any]

Returns

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

cancel

IBMQJob.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

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

cancelled

IBMQJob.cancelled()

Return whether the job has been cancelled.

Return type

bool

circuits

IBMQJob.circuits()

Return the circuits or pulse schedules for this job.

Return type

List[Union[QuantumCircuit, Schedule]]

Returns

The circuits or pulse schedules 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

IBMQJob.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

IBMQJob.done()

Return whether the job has successfully run.

Return type

bool

error_message

IBMQJob.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

IBMQJob.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

IBMQJob.in_final_state()

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

Return type

bool

job_id

IBMQJob.job_id()

Return the job ID assigned by the server.

Return type

str

Returns

Job ID.

name

IBMQJob.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

IBMQJob.properties()

Return the backend properties for this job.

Return type

Optional[BackendProperties]

Returns

The backend properties used for this job, or None if properties are not available.

Raises

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

qobj

IBMQJob.qobj()

Return the Qobj for this job.

Return type

Union[QasmQobj, PulseQobj, None]

Returns

The Qobj for this job, or None if the job does not have a Qobj.

Raises

IBMQJobApiError – If an unexpected error occurred when retrieving job information from the server.

queue_info

IBMQJob.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

IBMQJob.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

IBMQJob.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

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

Return type

None

result

IBMQJob.result(timeout=None, wait=5, partial=False, refresh=False)

Return the result of the job.

Note

Some IBM Quantum Experience 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 IBMQJob 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.
wait (float) – Time in seconds between queries.
partial (bool) – If True, return partial results if possible.
refresh (bool) – If True, re-query the server for the result. Otherwise return the cached value.

Return type

Result

Returns

Job result.

Raises

IBMQJobInvalidStateError – If the job was cancelled.
IBMQJobFailureError – If the job failed.
IBMQJobApiError – If an unexpected error occurred when communicating with the server.

running

IBMQJob.running()

Return whether the job is actively running.

Return type

bool

scheduling_mode

IBMQJob.scheduling_mode()

Return the scheduling mode the job is in.

The scheduling mode indicates how the job is scheduled to run. For example, fairshare indicates the job is scheduled using a fairshare algorithm.

This information is only available if the job status is RUNNING or DONE.

Return type

Optional[str]

Returns

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

share_level

IBMQJob.share_level()

Return the share level of the job.

The share level is one of global, hub, group, project, and none.

Return type

str

Returns

The share level of the job.

status

IBMQJob.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

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

submit

IBMQJob.submit()

Unsupported method.

Note

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

Raises

NotImplementedError – Upon invocation.

Return type

None

time_per_step

IBMQJob.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

IBMQJob.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.

Raises

IBMQJobApiError – If an unexpected error occurred when communicating with the server or updating the job name.
IBMQJobInvalidStateError – If the input job name is not a string.

update_tags

IBMQJob.update_tags(replacement_tags=None, additional_tags=None, removal_tags=None)

Update the tags associated with this job.

When multiple parameters are specified, the parameters are processed in the following order:

replacement_tags

additional_tags

removal_tags

For example, if ‘new_tag’ is specified for both additional_tags and removal_tags, then it is added and subsequently removed from the tags list, making it a “do nothing” operation.

Note

Some tags, such as those starting with ibmq_jobset, are used internally by ibmq-provider and therefore cannot be modified.
When removing tags, if the job does not have a specified tag, it will be ignored.

Parameters

replacement_tags (Optional[List[str]]) – The tags that should replace the current tags associated with this job.
additional_tags (Optional[List[str]]) – The new tags that should be added to the current tags associated with this job.
removal_tags (Optional[List[str]]) – The tags that should be removed from the current tags associated with this job.

Return type

List[str]

Returns

The new tags associated with this job.

Raises

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

wait_for_final_state

IBMQJob.wait_for_final_state(timeout=None, wait=None, callback=None)

Wait until the job progresses to a final state such as DONE or ERROR.

Parameters

timeout (Optional[float]) – Seconds to wait for the job. If None, wait indefinitely.
wait (Optional[float]) – Seconds to wait between invoking the callback function. If None, the callback function is invoked only if job status or queue position has changed.
callback (Optional[Callable]) –

Callback function invoked after each querying iteration. The following positional arguments are provided to the callback function:
- job_id: Job ID
- job_status: Status of the job from the last query.
- job: This IBMQJob instance.
In addition, the following keyword arguments are also provided:
- queue_info: A QueueInfo instance with job queue information, or None if queue information is unknown or not applicable. You can use the to_dict() method to convert the QueueInfo instance to a dictionary, if desired.

Raises

IBMQJobTimeoutError – if the job does not reach a final state before the specified timeout.

Return type

None

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.

experiment_id

Return the experiment ID.

Return type

str

Returns

ID of the experiment this job is part of.

version

Default value: 1

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