concurrency_fail.py

from random import randint
import gevent

def mightfail():
    x = randint(1, 10)
    if x == 10:
        raise ValueError("that's too big")
    return x

jobs = [gevent.spawn(mightfail) for x in xrange(50)]
gevent.joinall(jobs, timeout=2)

jobs_that_succeeded = filter(lambda job: job.successful(), jobs)
jobs_that_failed = filter(lambda job: not job.successful(), jobs)

print [job.value for job in jobs_that_succeeded]