这是Python 2.7。我已成功尝试了文档代码:
from multiprocessing import Pool
def f(x):
return x*x
if __name__ == '__main__':
pool = Pool(processes=4) # start 4 worker processes
result = pool.apply_async(f, [10]) # evaluate "f(10)" asynchronously
print result.get(timeout=1) # prints "100" unless your computer is *very* slow
print pool.map(f, range(10)) # prints "[0, 1, 4,..., 81]"
然后我为自己开发了一个非常简单的例子:
import multiprocessing
def run_test_n(n):
print 'inside test %d' % n
with open('test%d.log' % n, 'w') as f:
f.write('test %d ok\n' % n)
def runtests(ntests, nprocs):
pool = multiprocessing.Pool(processes = nprocs)
print 'runnning %d tests' % ntests
print 'over %d procs' % nprocs
tasks = range(1, ntests + 1)
results = [pool.apply_async(run_test_n, t) for t in tasks]
for r in results:
r.wait()
if __name__ == '__main__':
runtests(5,5)
在此示例中,不会创建任何文件,也不会打印“内部测试...”字符串。
就好像从未调用run_test_n(实际上从未调用过)。为什么呢?
答案 0 :(得分:1)
results = [pool.apply_async(run_test_n, t) for t in tasks]
你错了;正确的表格是results = [pool.apply_async(run_test_n, (t, )) for t in tasks]