Python Tutorial on Multithreading
alex.kapps at web.de
Mon Feb 21 18:04:32 EST 2011
On 21.02.2011 23:30, KevinSimonson wrote:
> I've been teaching myself Python from the tutorial routed at "http://
> www.tutorialspoint.com/python/index.htm". It's worked out pretty
> well, but when I copied its multithreading example from the bottom of
> the page at "http://www.tutorialspoint.com/python/
> python_multithreading.htm" and tried to run it I got the error
> C:\Users\kvnsmnsn\Python>python mt.py
> Traceback (most recent call last):
> File "mt.py", line 38, in<module>
> thread = myThread(threadID, tName, workQueue)
> File "mt.py", line 10, in __init__
> self.name = name
> File "C:\Python27\lib\threading.py", line 667, in name
> assert self.__initialized, "Thread.__init__() not called"
> AssertionError: Thread.__init__() not called
> I don't really understand why it's giving me these messages.
> <__initialized> gets set to<True> when<__init__()> gets called.
> Granted my Python program calls<__init__()> with only one parameter,
> and the constructor in "threading.py" takes _seven_ parameters, but
> all but one have default values, so a call with just one parameter
> should be legal. Why then is<__initialized> getting set to<True>?
> My code follows.
That tutorial seems to be wrong.
According to the official docs:
"If the subclass overrides the constructor, it must make sure to
invoke the base class constructor (Thread.__init__()) before doing
anything else to the thread."
So, change your __init__ to this:
class myThread (threading.Thread):
def __init__(self, threadID, name, q):
self.threadID = threadID
self.name = name
self.q = q
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