Python Popen - 未知参数：|

Question

使用下面的脚本时，我得到Unknown argument: |，我不确定它为什么不喜欢|。我在Windows上，与Python 2.7.11：

import subprocess 
from subprocess import Popen, PIPE, STDOUT 
import time 

command = 'VSPipe.exe --y4m script.vpy - | ffmpeg.exe -f yuv4mpegpipe -i - -c:v prores -an output.mov' 

process1 = Popen(command, stderr=PIPE, shell=False) 

while True: 
    line = process1.stderr.readline().decode('utf-8') 
    print line 
    time.sleep(2) 

UPDATE： 使用建议下面我现在已经尝试过这一点，但我正在逐渐pipe:: Operation not permitted。我究竟做错了什么？

import subprocess 
from subprocess import Popen, PIPE, STDOUT 
import time 

command1 = 'VSPipe.exe --y4m script.vpy -' 
command2 = 'ffmpeg.exe -f yuv4mpegpipe -i - -c:v prores -an output.mov' 

process1 = Popen(command1, stdout=PIPE) 
process2 = Popen(command2, stdin=process1.stdout, stderr=PIPE) 

print process2.communicate() 

另一个更新： 因此，使用下面的建议，并尝试其他的东西，我一直得到相同的结果pipe:: Operation not permitted。下面是完整的sdterr，还有什么我可以试试：

"F:/ffmpeg/VapourSynth/VSPipe.exe" --y4m "C:/Users/myself/Desktop/script.vpy" - 
"F:/ffmpeg/ffmpeg.exe" -f yuv4mpegpipe -i - -c:v prores -an -y "//192.168.0.100/media/temp/OutMov.mov" 
ffmpeg version N-77203-gb8e5b1d Copyright (c) 2000-2015 the FFmpeg developers 
    built with gcc 5.2.0 (GCC) 
    configuration: --arch=x86 --target-os=mingw32 --cross-prefix=/Users/myself/Desktop/Download/ffmpeg-windows-build-helpers-master/sandbox/mingw-w64-i686/bin/i686-w64-mingw32- --pkg-config=pkg-config --disable-w32threads --enable-gpl --enable-libsoxr --enable-fontconfig --enable-libass --enable-libutvideo --enable-libbluray --enable-iconv --enable-libtwolame --extra-cflags=-DLIBTWOLAME_STATIC --enable-libzvbi --enable-libcaca --enable-libmodplug --extra-libs=-lstdc++ --extra-libs=-lpng --enable-libvidstab --enable-libx265 --enable-decklink --extra-libs=-loleaut32 --enable-libx264 --enable-libxvid --enable-libmp3lame --enable-version3 --enable-zlib --enable-librtmp --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libopenjpeg --enable-gnutls --enable-libgsm --enable-libfreetype --enable-libopus --enable-frei0r --enable-filter=frei0r --enable-libvo-aacenc --enable-bzlib --enable-libxavs --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-amrwbenc --enable-libschroedinger --enable-libvpx --enable-libilbc --enable-libwavpack --enable-libwebp --enable-libgme --enable-dxva2 --enable-libdcadec --enable-avisynth --enable-gray --enable-libopenh264 --extra-libs=-lpsapi --extra-cflags= --enable-static --disable-shared --prefix=/Users/myself/Desktop/Download/ffmpeg-windows-build-helpers-master/sandbox/mingw-w64-i686/i686-w64-mingw32 --enable-nonfree --enable-libfdk-aac --disable-libfaac --enable-nvenc --enable-runtime-cpudetect 
    libavutil  55. 10.100/55. 10.100 
    libavcodec  57. 17.100/57. 17.100 
    libavformat 57. 19.100/57. 19.100 
    libavdevice 57. 0.100/57. 0.100 
    libavfilter  6. 20.100/6. 20.100 
    libswscale  4. 0.100/4. 0.100 
    libswresample 2. 0.101/2. 0.101 
    libpostproc 54. 0.100/54. 0.100 
pipe:: Operation not permitted 

UPDATE： 而她是ffmpeg的报告：

F:/ffmpeg/ffmpeg.exe -f yuv4mpegpipe -i - -c:v prores -an -y //192.168.0.100/media/temp/OutMov.mov -report 
ffmpeg version N-77203-gb8e5b1d Copyright (c) 2000-2015 the FFmpeg developers 
    built with gcc 5.2.0 (GCC) 
    configuration: --arch=x86 --target-os=mingw32 --cross-prefix=/Users/myself/Desktop/Download/ffmpeg-windows-build-helpers-master/sandbox/mingw-w64-i686/bin/i686-w64-mingw32- --pkg-config=pkg-config --disable-w32threads --enable-gpl --enable-libsoxr --enable-fontconfig --enable-libass --enable-libutvideo --enable-libbluray --enable-iconv --enable-libtwolame --extra-cflags=-DLIBTWOLAME_STATIC --enable-libzvbi --enable-libcaca --enable-libmodplug --extra-libs=-lstdc++ --extra-libs=-lpng --enable-libvidstab --enable-libx265 --enable-decklink --extra-libs=-loleaut32 --enable-libx264 --enable-libxvid --enable-libmp3lame --enable-version3 --enable-zlib --enable-librtmp --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libopenjpeg --enable-gnutls --enable-libgsm --enable-libfreetype --enable-libopus --enable-frei0r --enable-filter=frei0r --enable-libvo-aacenc --enable-bzlib --enable-libxavs --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvo-amrwbenc --enable-libschroedinger --enable-li libavutil  55. 10.100/55. 10.100 
    libavcodec  57. 17.100/57. 17.100 
    libavformat 57. 19.100/57. 19.100 
    libavdevice 57. 0.100/57. 0.100 
    libavfilter  6. 20.100/6. 20.100 
    libswscale  4. 0.100/4. 0.100 
    libswresample 2. 0.101/2. 0.101 
    libpostproc 54. 0.100/54. 0.100 
Splitting the commandline. 
Reading option '-f' ... matched as option 'f' (force format) with argument 'yuv4mpegpipe'. 
Reading option '-i' ... matched as input file with argument '-'. 
Reading option '-c:v' ... matched as option 'c' (codec name) with argument 'prores'. 
Reading option '-an' ... matched as option 'an' (disable audio) with argument '1'. 
Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'. 
Reading option '//192.168.0.100/media/temp/OutMov.mov' ... matched as output file. 
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'. 
Finished splitting the commandline. 
Parsing a group of options: global . 
Applying option y (overwrite output files) with argument 1. 
Applying option report (generate a report) with argument 1. 
Successfully parsed a group of options. 
Parsing a group of options: input file -. 
Applying option f (force format) with argument yuv4mpegpipe. 
Successfully parsed a group of options. 
Opening an input file: -. 
[AVIOContext @ 006d9800] Statistics: 0 bytes read, 0 seeks 
pipe:: Operation not permitted 

UPDATE： 使用此代码，我仍然得到同样的结果pipe:: Operation not permitted ：

import subprocess 
import os 
from subprocess import Popen, PIPE, STDOUT 
import shlex 

VsPipe = 'F:/ffmpeg/VapourSynth/VSPipe.exe' 
vpyScript = 'C:/Users/myself/Desktop/Boychoir-preview_SMALL_JobID_189.vpy' 
ffmpeg = 'F:/ffmpeg/ffmpeg.exe' 
outputPath = '//192.168.0.100/media/temp/OutMov.mov' 

command1 = shlex.split('"%s" --y4m "%s" - ' % (VsPipe, vpyScript)) 
command2 = shlex.split('"%s" -f yuv4mpegpipe -i - -c:v prores -an -y "%s" -report' % (ffmpeg, outputPath)) 

process1 = subprocess.Popen(command1, stdout=subprocess.PIPE) 
ls_out, _ = process1.communicate() 
process2 = subprocess.Popen(command2, stdin=subprocess.PIPE, stderr=subprocess.PIPE) 

grep_out, grep_err = process2.communicate(input=ls_out) 
print grep_err 

UPDATE： 固定的，竟然是一个文件路径权限问题，谢谢FO所有的帮助。

Answer 1

当您将shell设置为False时，args（即第一个）参数应该是程序的名称（如果它是字符串的话）。否则，它应该是一串字符串，第一个是程序，其余的是参数。

使用管道时，外壳的重要性在于，在该行：

VSPipe.exe --y4m script.vpy - | ffmpeg.exe -f yuv4mpegpipe -i - -c:v prores -an output.mov 

都没有考虑的参数。 VSPipe.exe的参数是--y4m和script.vpy。 ffmpeg.exe的参数是-f,yuv4mpegpipe,-i等shell是什么处理管道 - 它启动两个程序（提供他们的参数），但它通过首先创建一个管道，使stdout从第一个连接到stdin第二。

如果你没有支持管道的shell，你可以通过启动它们来模拟python，然后将输出从第一个输出到第二个。

Answer 2

从子docs：

使用POPEN用，当你需要管道通信（）方法。

大厦@ skyking的回答和更新的代码，它看起来像你只需要使用通信（）：

# Simple Windows script to confirm existence of Desktop directory in users home space 
# ls -al | grep Desktop 
# This requires Windows Git to be installed for unix utils like ls, grep 

# NOTE: you may have problems with this if you're using built in Windows shell 
# utilities like dir etc.. This is because these are built into the shell and 
# aren't executables on your path. Use shell=True if you have to use these. 

import os 
import subprocess 

# Change to home directory 
os.chdir(os.path.expanduser("~")) 

# Command parameters sent to Popen initializer should be lists 
# Here we are only interested in the output so PIPE stdout 
ls_process = subprocess.Popen(['ls', '-al'], stdout=subprocess.PIPE) 

# When working with subprocess PIPE we need to use the communicate() method 
# We're only interested in stdout so _ is used to throw away stderr (which will be 
# None anyway since we didn't pipe stderr) 
ls_out, _ = ls_process.communicate() 

# We then create our second process but this time we're interested in piping the 
# first command into stdin, using stdout and potentially stderr if there was a problem 
grep_process = subprocess.Popen(['grep', 'Desktop'], 
            stdin=subprocess.PIPE, 
            stdout=subprocess.PIPE, 
            stderr=subprocess.PIPE) 

# We use communicate() again but this time we give the output string of the first command 
# as a parameter to communicate() 
grep_out, grep_err = grep_process.communicate(input=ls_out) 

print grep_out 

子过程是一个艰难的模块来获得正确的第一时间，我们很高兴地看在其他项目中使用它的实例。

另一个好的提示是尽量保持平台独立的东西。即使你不打算在Windows以外的任何地方运行它，它也会帮助你避免你正在使用的系统的特性。

Answer 3

首先，我会建议你到用户完整路径的所有.exe这里我用来做到这一点的代码。

import os 
import re 
import subprocess 
from subprocess import Popen, PIPE, STDOUT 
import shlex 

def _get_locate_command_result(bin_name, 
           which_command="which", default_path=""): 
    # check_output returns bytes for python3 and str for py2 
    try: 
     result_locate = subprocess.check_output(
      shlex.split("%s %s" % (which_command, bin_name)), env=os.environ) 
     result_locate_table = re.split(r"\r?\n", result_locate.decode()) 
     try: 
      bin_path = result_locate_table[0].strip() 
     except IndexError: 
      bin_path = bin_name 
     return bin_path 


    except subprocess.CalledProcessError: 
     return default_path 

对于Windows：

path = get_locate_command_result(bin_name, which_command="where", default_path=default_path) 

所以，你可以尝试类似的东西（未测试）：

# use "" beacause of '\' 
command1 = ('"%s" --y4m script.vpy -' 
      % _get_locate_command_result("VSPipe.exe", "where", "VSPipe.exe")) 
command2 = ('"%s" -f yuv4mpegpipe -i - -c:v prores -an output.mov' 
      % _get_locate_command_result("VSPipe.exe", "where", "ffmpeg.exe")) 

# Popen needs sequence of string 
cmd1 = shlex.split(command1) 
cmd2 = shlex.split(command2) 

process1 = Popen(cmd1, stdout=PIPE) 
process2 = Popen(cmd2, stdin=process1.stdout, stderr=PIPE) 

print(process2.communicate())