how to write python concurrent future and retry correctly? Tableau API

I am a newbie to concurrent. I am trying to refresh 3 workbooks in Tableau:

    workbook_dict = {"workbook1":"workbook_id1","workbook2":"workbook_id2","workbook3":"workbook_id3"}

    @retry(tries=3, delay=5, backoff=0.2)
    def refresh_workbooks(self, workbook_dict):
        for workbook_name, workbook_id in workbook_dict.items():
            workbook = self.server.workbooks.get_by_id(workbook_id)

            #refresh will fire up the refresh, and return job_id object
            job_id = self.server.workbooks.refresh(workbook)

            #wait_for job will check the status and raise exception if fails or timeout
            #https://tableau.github.io/server-client-python/docs/api-ref#jobswait_for_job

            self.server.jobs.wait_for_job(job_id,timeout=1000)

This base code totally works and each workbook takes 15mins, so totally 45min to complete; And if it fails on the second workbook, it will start over from scratch.

I want to use concurrent to speed up and check wait_for_job. And if any fails then refresh only that workbook, retry a few times before throwing errors. First question: The below code is my attempt to try concurrent but the printed data object returns None. I think the code failed to execute the wait_for job Why is that?

import concurrent.futures
import urllib.request
import tableauserverclient as TSC

def refresh_workbook(self, workbook_id):
    workbook = self.server.workbooks.get_by_id(workbook_id)
    job_id = self.server.workbooks.refresh(workbook)
    return job_id

def refresh_workbooks(self, workbook_dict):
    job_dict = {}
    try:
        for workbook_name, workbook_id in workbook_dict.items():
            workbook = self.server.workbooks.get_by_id(workbook_id)
            job_id = self.server.workbooks.refresh(workbook)
            job_dict[workbook_name] = job_id.id
            print(job_dict)
    except:
        raise

    return job_dict


def wait_workbook(self, job_id, timeout=None):
    self.server.jobs.wait_for_job(job_id, timeout=timeout)


test = TableauServerConnection()
workbook_dict = {"workbook1":"workbook_id1","workbook2":"workbook_id2","workbook3":"workbook_id3"}
jobs = test.refresh_workbooks(workbook_dict)


with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
    
    future_to_job = {executor.submit(test.wait_workbook, job_id, 1800): job_id for workbook_name, job_id in jobs.items()}
    for future in concurrent.futures.as_completed(future_to_job):
        job = future_to_job[future]
        try:
            data = future.result()
            #Why did I get None in data? 
            print('data',data)
        except Exception as exc:
            #can I spin up new future here and what is the correct syntax?

            print('%s generated an exception: %s' % (job, exc))
        else:
            print('job', job)

Secondly, if I add retry in exception, could I add new future object there?

from how to write python concurrent future and retry correctly? Tableau API