Writing to a file with multiprocessing

Question

I\'m having the following problem in python.

I need to do some calculations in parallel whose results I need to be written sequentially in a file. So I created a fu

Answer 1

You really should use two queues and three separate kinds of processing.

1. Put stuff into Queue #1.

2. Get stuff out of Queue #1 and do calculations, putting stuff in Queue #2. You can have many of these, since they get from one queue and put into another queue safely.

3. Get stuff out of Queue #2 and write it to a file. You must have exactly 1 of these and no more. It "owns" the file, guarantees atomic access, and absolutely assures that the file is written cleanly and consistently.