python - 使用 python 进行子进程管理

Question

我有一个数据分析脚本，它接受一个参数来指定要执行的分析部分。我想一次运行最多“n”个脚本实例，其中“n”是机器上的核心数。复杂的是分析的部分多于核心，所以我想一次最多运行“n”个进程，其中一个完成，启动另一个。有没有人在使用 subprocess 模块之前做过这样的事情？

Answer 1

我认为 multiprocessing 模块将帮助您实现您的需求。 查看示例技术。

import multiprocessing

def do_calculation(data):
    """
    @note: you can define your calculation code
    """
    return data * 2

def start_process():
    print 'Starting', multiprocessing.current_process().name

if __name__ == '__main__':
    analsys_jobs = list(range(10))  # could be your analysis work
    print 'analsys_jobs :', analsys_jobs

    pool_size = multiprocessing.cpu_count() * 2
    pool = multiprocessing.Pool(processes=pool_size,
                                initializer=start_process,
                                maxtasksperchild=2, ) 
    #maxtasksperchild = tells the pool to restart a worker process \
    # after it has finished a few tasks. This can be used to avoid \ 
    # having long-running workers consume ever more system resources

    pool_outputs = pool.map(do_calculation, analsys_jobs)   
    #The result of the map() method is functionally equivalent to the \
    # built-in map(), except that individual tasks run in parallel. \
    # Since the pool is processing its inputs in parallel, close() and join()\
    # can be used to synchronize the main process with the \
    # task processes to ensure proper cleanup.  

    pool.close() # no more tasks
    pool.join() # wrap up current tasks


    print 'Pool :', pool_outputs

你可以找到好的multiprocessing techniques here开始