Python 多处理错误

Question

我是 Python 多重处理新手。我有下面的代码，非常简单。但它不起作用!它只打印开始和结束。它从不打印“Into Run”。我缺少什么？我在 Windows 上，Python 2.6

import logging, sys
from multiprocessing import Process

class ZincDataExtract(Process):
    def __init__(self, sources=None):
        Process.__init__(self)
        if sources is None:
            self.src = 'Everything'
        else:
            self.src = sources

    def run(self):
        print "Into Run: " + str(self.src)
        sys.stdout.flush()

def main():

    from datetime import datetime
    cobDate = datetime.strptime('2013-11-29', '%Y-%m-%d').date()

    logging.info("Start: " + datetime.now().strftime('%Y-%m-%d %H:%M:%S'))

    procs = []
    sources='CRE,Mortgage,OGRE,RV2,TDR,Tiger,CIDW'
    p1 = Process(target=ZincDataExtract, args=(sources))
    procs.append(p1)
    p1.start()

    sources='RAM'
    p2 = Process(target=ZincDataExtract, args=(sources))
    procs.append(p2)
    p2.start()

    for p in procs:
        p.join()

    logging.info("End: " + datetime.now().strftime('%Y-%m-%d %H:%M:%S'))

Answer 1

当您扩展 multiprocessing.Process 类时，您应该将 ZincDataExtract 视为该类本身。您已经在调用父类(super class)的 __init__() 方法(第 5 行)，因此您不需要实例化两个 Process 类。

要使代码正常工作，请更改以下行:

p1 = Process(target=ZincDataExtract, args=(sources))
...
p2 = Process(target=ZincDataExtract, args=(sources))

致:

p1 = ZincDataExtract(sources)
...
p2 = ZincDataExtract(sources)

这将创建两个 ZincDataExtract 实例，而不是两个 Process 实例，并且代码将起作用!