TypeError:execv()arg 2必须仅包含使用docopt的字符串

Question

我在传递参数时遇到以下错误。有人能帮我找出这个问题吗？我在终端中向我的功能传递指令，如下所示：

python makeQuicktime.py -i /Volumes/P003A/TM_Cloud/Nagrania/Karta_04/XDROOT/Clip/D004C010_141026MM.MXF -f 25 -c prores

这是main函数——正如您所看到的，我试图将参数——编解码器传递为字符串：

if __name__ == "__main__":
    args = docopt(__doc__, version='makeQuicktime 0.0.1')
    print args
    cmd_args = ""
    codec=str(args['--codec'])
    makeQuicktime( args['--input'], fps=args['--fps'], codec=str(args['--codec']) )
    os._exit(0)

该代码正在运行的其他函数的部分（makeProRes，第110行是输出变量）：

subprocess.call([FFMPEG_PATH, 'i', input,
    '-start_number', start_frame, '-r', fps,
    '-c:v', 'prores',
    '-profile:v', '2',
    '-c:a', 'copy',
    '-threads', cpus,
    output
  ])

错误：

Traceback (most recent call last):
  File "makeQuicktime.py", line 123, in <module>
    makeQuicktime( args['--input'], fps=args['--fps'], codec=str(args['--codec']) )
  File "makeQuicktime.py", line 53, in makeQuicktime
    makeProRes(1, input, fps, output)
  File "makeQuicktime.py", line 110, in makeProRes
    output
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 524, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 711, in __init__
    errread, errwrite)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1308, in _execute_child
    raise child_exception
TypeError: execv() arg 2 must contain only strings

Answer 1

start_frame、fps或cpus中的一个是数字，而不是字符串。找到后，将其封装在str()中进行转换。