Python - 对已关闭文件的子进程 I/O 操作

Question

我尝试过下面的类，使用python2.6中的subporcess模块​​按顺序执行命令。

from subprocess import Popen, PIPE

class BaculaActions():

    def __init__(self):
        self.console = Popen(["bconsole"], stdout=PIPE, stderr=PIPE, stdin=PIPE)

    def run_job(self, jobname, level):
        run = self.console.communicate("run job=%s level=%s yes" % (jobname, level))
        return(run)

    def del_jobid(self, jobid):
        delete = self.console.communicate("delete jobid=%s" % (jobid))
        return(delete)

但是，如果我尝试以下代码，则会收到错误:ValueError:对已关闭文件进行 I/O 操作

from pconsole import BaculaActions

myconsole = BaculaActions()

run = myconsole.run_job("xxxxx-data", "incremental")
delete = myconsole.del_jobid(25487)

有人知道可能出了什么问题吗？谢谢

Answer 1

手册确实说明了一切:

Popen.communicate(input=None, timeout=None)
Interact with process: Send data to stdin. Read data from stdout and stderr, 
until end-of-file is reached. Wait for process to terminate.

运行第一个命令并获得结果后，“bconsole”进程已终止，管道已关闭，因此第二个communicate 调用时出现错误。