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Running windows shell commands with python

How can we interact with OS shell using Python ? I want to run windows cmd commands via python. How can it be achieved ?

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The newer `subprocess.check_output` and similar commands are supposed to replace `os.system`. See [this page][1] for details. While I can't test this on Windows (because I don't have access to any Windows machines), the following should work:

 from subprocess import check_output
 check_output("dir C:", shell=True)

`check_output` returns a string of the output from your command. Alternatively, `subprocess.call` just runs the command and returns the status of the command (usually 0 if everything is okay).

Also note that, in python 3, that string output is now `bytes` output. If you want to change this into a string, you need something like

 from subprocess import check_output
 check_output("dir C:", shell=True).decode()

If necessary, [you can tell it](https://docs.python.org/3/library/stdtypes.html#bytes.decode) the kind of encoding your program outputs. The default is `utf-8`, which typically works fine, but other standard options are [here](https://docs.python.org/3/library/codecs.html#standard-encodings).

Also note that @bluescorpion says in the comments that Windows 10 needs a trailing backslash, as in `check_output("dir C:\\", shell=True)`. The double backslash is needed because `\` is a special character in python, so it has to be [escaped](https://docs.python.org/3.8/reference/lexical_analysis.html#index-22). (Also note that even prefixing the string with `r` doesn't help if `\` is the very last character of the string — `r"dir C:\"` is a syntax error, though `r"dir C:\ "` is not.)

 [1]: http://docs.python.org/2/library/subprocess.html

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This works in Windows 7. Thanks. It does return \r\n at the end of the string, so you might need to strip that out with a [0:-2] substring.

Bill N
– Bill N

2015年04月17日 18:49:23 +00:00
Commented Apr 17, 2015 at 18:49
7

Using [0:-2] for that purpose makes me nervous. If anyone takes that code to apply it in a non-Windows context, they'll certainly change the obvious dir C: to ls or whatever. But they could easily fail to realize that [0:-2] should be changed to [0:-1]. I'd recommend .rstrip() instead, which would work on any platform (unless you want to capture other trailing whitespace), and also makes the reason behind the string alteration clearer.

Mike
– Mike

2015年05月18日 14:11:35 +00:00
Commented May 18, 2015 at 14:11
@Mikw: I have a windows command which is used for deployment.Just a single line of command. How can I call it from an external python3.4 script

Nevin Raj Victor
– Nevin Raj Victor

2015年06月04日 04:54:21 +00:00
Commented Jun 4, 2015 at 4:54
2

Works in Win 10 with a slight modification: check_output("dir C:\\", shell=True)

blue scorpion
– blue scorpion

2017年11月15日 16:56:45 +00:00
Commented Nov 15, 2017 at 16:56
1

@codingbruh Yes. In fact (as I noted in a previous comment), I don't even have access to any windows machines. I use it routinely on macOS and various species of linux without any trouble. You just need to give it commands that the shell will understand — e.g., ls / instead of dir C:.

Mike
– Mike

2022年11月21日 21:10:35 +00:00
Commented Nov 21, 2022 at 21:10

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Running windows shell commands with python

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