Python 子进程 Popen:为什么会出现“ls *.txt"?不行?

问题描述

我正在查看这个问题.

就我而言，我想做一个:

In my case, I want to do a :

import subprocess
p = subprocess.Popen(['ls', 'folder/*.txt'], stdout=subprocess.PIPE, 
                                 stderr=subprocess.PIPE)

out, err = p.communicate()

现在我可以在命令行上检查执行ls 文件夹/*.txt"是否有效，因为该文件夹有许多 .txt 文件.

Now I can check on the commandline that doing a "ls folder/*.txt" works, as the folder has many .txt files.

但在 Python (2.6) 中我得到:

But in Python (2.6) I get:

ls: 无法访问 * : 没有这样的文件或目录

我尝试过这样做:r'文件夹/*.txt'r"文件夹/*.txt"r'文件夹/\*.txt'和其他变体，但似乎 Popen 根本不喜欢 * 字符.

I have tried doing: r'folder/*.txt' r"folder/*.txt" r'folder/\*.txt' and other variations, but it seems Popen does not like the * character at all.

还有其他方法可以逃脱*吗?

Is there any other way to escape *?

推荐答案

*.txt会被你的shell自动扩展成file1.txt file2.txt ....如果引用*.txt，则不起作用:

*.txt is expanded by your shell into file1.txt file2.txt ... automatically. If you quote *.txt, it doesn't work:

[~] ls "*.py"                                                                  
ls: cannot access *.py: No such file or directory
[~] ls *.py                                                                    
file1.py  file2.py file3.py

如果您想获取与您的模式匹配的文件，请使用 glob:

If you want to get files that match your pattern, use glob:

>>> import glob
>>> glob.glob('/etc/r*.conf')
['/etc/request-key.conf', '/etc/resolv.conf', '/etc/rc.conf']

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