t.py

from threading import Thread
import random
import time

tasks = [f'task-{num}' for num in range(1,5)]

def do_task(t):

    def try_do_task():
        time.sleep(1)
        if random.random() > 0.2:
            print(f'{t} Done\n')
        else:
            print(f'{t} Failed, Restarting\n')
            raise IOError

    while True:
        try:
            try_do_task()
            break
        except:
            continue

threads = [
    Thread(target=do_task, args=(task,))
    for task in tasks
]

for thread in threads:
    thread.start()

for thread in threads:
    thread.join()