Python 2.7:如何补偿丢失的pool.starmap?

时间:2018-10-04 16:27:59

标签: python python-2.7 arguments multiprocessing python-multiprocessing

我已经定义了此功能

def writeonfiles(a,seed):
    random.seed(seed)

    f = open(a, "w+")
    for i in range(0,10):
        j = random.randint(0,10)
        #print j
        f.write(j)
    f.close()

其中a是包含文件路径的字符串,seed是整数种子。 我想以一种这样的方式并行化一个简单的程序,即每个内核都采用我提供的可用路径之一,播种其随机数生成器并在该文件上写入一些随机数,例如,如果我通过了 向量

vector = [Test/file1.txt, Test/file2.txt] 

和种子

seeds = (123412, 989898), 

它将功能赋予第一个可用的核心

writeonfiles(Test/file1.txt, 123412) 

和第二个相同的函数带有不同的参数:

writeonfiles(Test/file2.txt, 989898)

我在Stackoverflow上浏览了很多类似的问题,但是我无法解决任何问题。 我试过的是:

def writeonfiles_unpack(args):
    return writeonfiles(*args)
if __name__ == "__main__":
     folder = ["Test/%d.csv" %i for i in range(0,4)]
     seed = [234124, 663123, 12345 ,123833]
     p = multiprocessing.Pool()
     p.map(writeonfiles, (folder,seed))

并给我TypeError:writeonfiles()恰好接受2个参数(给定1个)。

我也尝试过

if __name__ == "__main__":
    folder = ["Test/%d.csv" %i for i in range(0,4)]
    seed = [234124, 663123, 12345 ,123833]
    p = multiprocessing.Process(target=writeonfiles, args= [folder,seed])
    p.start()

但这给了我
  种子中的文件“ /usr/lib/python2.7/random.py”,第120行     超级(随机,自我)。种子(a) TypeError:无法散列的类型:“列表”

最后,我尝试了contextmanager

 @contextmanager
 def poolcontext(*args, **kwargs):
     pool = multiprocessing.Pool(*args, **kwargs)
     yield pool
     pool.terminate()

if __name__ == "__main__":
    folder = ["Test/%d" %i for i in range(0,4)]
    seed = [234124, 663123, 12345 ,123833]
    a = zip(folder, seed)
    with poolcontext(processes = 3) as pool:
    results = pool.map(writeonfiles_unpack,a )

,结果为   在get中的文件“ /usr/lib/python2.7/multiprocessing/pool.py”,第572行     提高自我价值

TypeError:“模块”对象不可调用

1 个答案:

答案 0 :(得分:3)

Python 2.7缺少Python 3.3+中的import os from multiprocessing import Pool import random from functools import wraps def unpack(func): @wraps(func) def wrapper(arg_tuple): return func(*arg_tuple) return wrapper @unpack def write_on_files(a, seed): random.seed(seed) print("%d opening file %s" % (os.getpid(), a)) # simulate for _ in range(10): j = random.randint(0, 10) print("%d writing %d to file %s" % (os.getpid(), j, a)) # simulate if __name__ == '__main__': folder = ["Test/%d.csv" % i for i in range(0, 4)] seed = [234124, 663123, 12345, 123833] arguments = zip(folder, seed) pool = Pool(4) pool.map(write_on_files, iterable=arguments) pool.close() pool.join() 池方法。您可以通过使用包装器装饰目标函数来克服此问题,该包装器将对参数元组进行解包并调用目标函数:

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