This does not call test in a new thread: thread = threading.Thread(target=test(“Test”)) thread.start() Here’s how Python interprets those lines of code: Main thread calls test(“Test”). test(“Test”) returns None. Main thread calls Thread(target=None).* Main thread starts the new thread. New thread does absolutely nothing at all because its target is None. Edit: *I wondered why Thread(targe=None) … Read more
Since this question was asked in 2010, there has been real simplification in how to do simple multithreading with Python with map and pool. The code below comes from an article/blog post that you should definitely check out (no affiliation) – Parallelism in one line: A Better Model for Day to Day Threading Tasks. I’ll … Read more
threading.get_ident() works, or threading.current_thread().ident (or threading.currentThread().ident for Python < 2.6).
A good way is to have the main array beeing alocated ouside the threads. Then you give to each thread the pointer to the part of the main array that should be computed by the thread. The following example is an implementation of a matrix multiplication (similar to dot for 2-D arrays) where: c = … Read more
There’s no reason to let your threads die. If they’re actually crashing, your whole program will crash. If they’re just raising exceptions, you can just catch the exceptions. If they’re returning normally, you can just not do that. You can even trivially wrap a thread function to restart itself on exception or return: def threadwrap(threadfunc): … Read more
I don’t know if it’s the only problem with your code, but I can tell about threading — target has to be a function, instead you call functions, making them run in main thread. So if first function is an infinite loop — program will not create any threads, because it will stuck executing the … Read more
I suggest you instantiate a Queue.Queue before starting the thread, and pass it as one of the thread’s args: before the thread finishes, it .puts the result on the queue it received as an argument. The parent can .get or .get_nowait it at will. Queues are generally the best way to arrange thread synchronization and … Read more
Queue.Queue and collections.deque serve different purposes. Queue.Queue is intended for allowing different threads to communicate using queued messages/data, whereas collections.deque is simply intended as a datastructure. That’s why Queue.Queue has methods like put_nowait(), get_nowait(), and join(), whereas collections.deque doesn’t. Queue.Queue isn’t intended to be used as a collection, which is why it lacks the likes … Read more
A somewhat clumsy ascii-art to demonstrate the mechanism: The join() is presumably called by the main-thread. It could also be called by another thread, but would needlessly complicate the diagram. join-calling should be placed in the track of the main-thread, but to express thread-relation and keep it as simple as possible, I choose to place … Read more
Since this question was asked in 2010, there has been real simplification in how to do simple multithreading with Python with map and pool. The code below comes from an article/blog post that you should definitely check out (no affiliation) – Parallelism in one line: A Better Model for Day to Day Threading Tasks. I’ll … Read more