Does an in-thread uncaught exception kill only the thread or the whole process?

Question

When an exception is raised inside a thread without catching it anywhere else, will it then kill the whole application/interpreter/process? Or will it only kill the thread?

Answer 1

Let's try it:

import threading
import time

class ThreadWorker(threading.Thread):

    def run(self):
        print "Statement from a thread!"
        raise Dead


class Main:

    def __init__(self):
        print "initializing the thread"
        t = ThreadWorker()
        t.start()
        time.sleep(2)
        print "Did it work?"


class Dead(Exception): pass



Main()

The code above yields the following results:

> initializing the thread 
> Statement from a thread! 
> Exception in thread
> Thread-1: Traceback (most recent call last):   File
> "C:\Python27\lib\threading.py", line 551, in __bootstrap_inner
>     self.run()   File ".\pythreading.py", line 8, in run
>     raise Dead Dead
> ----- here the interpreter sleeps for 2 seconds -----
> Did it work?

So, the answer to your question is that a raised Exception crashes only the thread it is in, not the whole program.