python-multiprocessing

来源： https://stackoverflow.com/questions/58368682/python-multiprocessing-a-large-dataframe-on-linux

来源： https://stackoverflow.com/questions/58368682/python-multiprocessing-a-large-dataframe-on-linux

来源： https://stackoverflow.com/questions/63205467/combining-asyncio-with-multiprocessing

问题 I am trying to use a ProcessPoolExecutor, but I am getting the error "Queue objects should only be shared between processes through inheritance", but I am not using a Queue (at least not explicitly). I can't find anything that explains what I am doing wrong. Here is some code that demonstrates the issue (not my actual code): from concurrent.futures import ProcessPoolExecutor, as_completed class WhyDoesntThisWork: def __init__(self): self.executor = ProcessPoolExecutor(4) def execute_something

问题 I am trying to use a ProcessPoolExecutor, but I am getting the error "Queue objects should only be shared between processes through inheritance", but I am not using a Queue (at least not explicitly). I can't find anything that explains what I am doing wrong. Here is some code that demonstrates the issue (not my actual code): from concurrent.futures import ProcessPoolExecutor, as_completed class WhyDoesntThisWork: def __init__(self): self.executor = ProcessPoolExecutor(4) def execute_something

问题 What i am trying to do is to make use of global variable by each process. But my process is not taking the global values import multiprocessing count = 0 def smile_detection(thread_name): global count for x in range(10): count +=1 print thread_name,count return count x = multiprocessing.Process(target=smile_detection, args=("Thread1",)) y = multiprocessing.Process(target=smile_detection, args=("Thread2",)) x.start() y.start() I am getting output like Thread1 1 Thread1 2 . . Thread1 9 Thread1

问题 I'm currently trying to run a parallel process in python 3.5 using the joblib library with the multiprocessing backend. However, every time it runs I get this error: Process ForkServerPoolWorker-5: Traceback (most recent call last): File "/opt/anaconda3/lib/python3.5/multiprocessing/process.py", line 249, in _bootstrap self.run() File "/opt/anaconda3/lib/python3.5/multiprocessing/process.py", line 93, in run self._target(*self._args, **self._kwargs) File "/opt/anaconda3/lib/python3.5

问题 I am using a multiprocessing.Pool which calls a function in 1 or more subprocesses to produce a large chunk of data. The worker process creates a multiprocessing.shared_memory.SharedMemory object and uses the default name assigned by shared_memory . The worker returns the string name of the SharedMemory object to the main process. In the main process the SharedMemory object is linked to, consumed, and then unlinked & closed . At shutdown I'm seeing warnings from resource_tracker : /usr/local

问题 I'm trying to learn the basics of multi-processing in python, and found the following example online which I wanted to practice with. import concurrent.futures import time def do_something(seconds): print(f' Sleeping {seconds} seconds') time.sleep(seconds) return f'Done Sleeping {seconds}' with concurrent.futures.ProcessPoolExecutor() as executor: f1 = executor.submit(do_something, 1) print(f1.result()) Fairly simple, I know. However, for some reason when I try and run this, I get the

问题 I'm trying to learn the basics of multi-processing in python, and found the following example online which I wanted to practice with. import concurrent.futures import time def do_something(seconds): print(f' Sleeping {seconds} seconds') time.sleep(seconds) return f'Done Sleeping {seconds}' with concurrent.futures.ProcessPoolExecutor() as executor: f1 = executor.submit(do_something, 1) print(f1.result()) Fairly simple, I know. However, for some reason when I try and run this, I get the