在多处理文件中导入错误

Question

我正在尝试使用python多处理模块处理大文件。执行下面的代码我得到模块导入错误。 在python2.7控制台上，“来自多处理导入池”工作正常。

from multiprocessing import Pool
import subprocess

def process_line(file):
    return "foo"

if __name__ == "__main__":
   pool = Pool(4)
   with open('file.txt') as source_file:
    # chunk the work into batches of 4 lines at a time
       results = pool.map(process_line, source_file, 4)

   print results

导入错误：