子流程中如何不引用参数? [英] How not to quote argument in subprocess?

问题描述

我正在尝试使用subprocess.call从Python 2.7调用ImageMagick命令.我的问题是子进程中的参数解析器在每个参数周围都加上了双引号，而ImageMagick似乎在非文件参数周围使用了引号.

I'm trying to call an ImageMagick command from Python 2.7 using subprocess.call. My problem is that the argument parser in subprocess puts a double quotation mark around every argument, and ImageMagick seems to have a problem with quotes around non-file arguments.

我想要的是这样的东西

"imagemagick.exe" "im1.png" "im2.png" -alpha off ( ... ) -composite "im3.png"

到目前为止，除了用丑陋的 +" + 元素手动构造字符串并使用 shell = True 来手工构造字符串之外，到目前为止，我找不到用子进程来完成此操作的方法.代码>.

So far I couldn't find a way to do it with subprocess, other than manually constructing the string with ugly + " " + elements and calling it with shell=True.

这是我的代码:

args = [    imagemagick,
            filename + "_b.bmp",
            filename + "_w.bmp",
            "-alpha off ( -clone 0,1 -compose difference -composite -negate ) ( -clone 0,2 +swap -compose divide -composite ) -delete 0,1 +swap -compose Copy_Opacity -composite",
            filename + ".png" ]   

subprocess.call( args )

有什么方法可以使用子进程调用没有双引号的正确命令吗?

Is there any way to call the correct command without double quotes using subprocess?

更新:插入了完整的命令行.我想把那部分放在一起，而不是"alpha"，-off"，……一一对应.

Update: inserted the full command line. I'd like to keep that part together, not as "alpha", "-off", ... one by one.

推荐答案

使用 subprocess 调用外部程序时， every 参数必须是 args的不同元素.因此，尝试:

When calling external programs with subprocess, every argument must be a different element of args. So try:

args = [    imagemagick,
            filename + "_b.bmp",
            filename + "_w.bmp",
            "-alpha", "off", "( ... )", "-composite",
            filename + ".png" ]

我不确定(...)代表什么，但是如果您在命令行中将未引号的空格放在其中，则它们应该是 args 也是如此.

I'm not sure what the ( ... ) represents, but if you put unquoted spaces in there on the command line, they should be separate elements in args too.

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