0

我试图在我的 python 脚本中执行这个命令：

avprobeCommand = "avprobe -of json -show_streams {0} | grep '\"duration\"' | sed -n 1p | sed 's/ //g'".format(hiOutput)
output = subprocess.check_output([avprobeCommand])

我不断得到：

    Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 552, in __bootstrap_inner
    self.run()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 505, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/Users/jmakaila/Documents/Development/Present/Web/video_dev/present-live-transcoder/Transcoder.py", line 60, in transcode
    output = subprocess.check_output([avprobeCommand])
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 537, in check_output
    process = Popen(stdout=PIPE, *popenargs, **kwargs)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 679, in __init__
    errread, errwrite)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1228, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

我已经尝试将 args 拆分，但我一直收到 -of json -show_streams 部分的错误，据记录，它看起来像这样：

subprocess.check_output(["avprobe", "-of json", "-show_streams", "{0}".format(hiOutput)
4

2 回答 2

1

将命令作为字符串传递，然后传递shell=True：

import pipes
import subprocess

avprobeCommand = """avprobe -of json -show_streams {0} | grep '"duration"' | sed -n 1p | sed 's/ //g'""".format(pipes.quote(hiOutput))
output = subprocess.check_output(avprobeCommand, shell=True)

更新：参数应该使用pipes.quote. （shlex.quote如果您使用 Python 3.3+，请使用）。

于 2013-10-19T03:47:17.990 回答
1

在您的情况下，您可以将后处理移至 Python：

import json
from subprocess import check_output as qx

data = json.loads(qx(["avprobe", "-of", "json", "-show_streams", hiOutput]))
result = data["duration"]         # grep '"duration"'
             .partition("\n")[0]  # sed -n 1p
             .replace(" ", "")    # sed 's/ //g'

对于更一般的情况，请参阅如何使用 subprocess.Popen 通过管道连接多个进程？

于 2013-10-24T11:36:58.850 回答