Can I get the job variable from the job_id？

Question

Suppose I run the following code：

job = execute(qc, backend = backend, shots = 1024, optimization_level = 0)

Then the job takes a long time to run. We know that job_id (from job.job_id()) is a unique identifier for a job. Can I just save job_id and then turn it off and restore the job variable with job_id the next day?

Or what information can I save that will allow me to get the job.result() after I drop the line?

The motivation for this problem is that I don't want to increase the workload due to network reasons when I am waiting for many tasks to run. It will be much easier to handle data when there is job.result(). Otherwise, I can only go to https://quantum-computing.ibm.com/ to download the result data, and the data format is not easy to use.

thank you for your help!

Answer 1

I take it you're running the jobs on an IBMQ backend and not one of the local simulators.
If so, just keep track of job_id, then use the retrieve_job function to retrieve the job at a later point in time and get its result.

Answer 2

In order to fully recover your Job object from IBMQ, you need two things:

• the backend name
• the job id

Once you sent your job, you can save those like this:

job_id = job.job_id()
backend_name = job.backend().name()

Later, when the job is done, you can recover the Job object like this:

provider = IBMQ.load_account()
job = provider.get_backend(backend_name).retrieve_job(job_id)