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1

How can I launch a bash command with multiple args (for example "sudo apt update") from a python script?

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2  
docs.python.org/3/library/subprocess.html – don_crissti Mar 16 '15 at 14:19
up vote 4 down vote accepted

@milne's answer works, but subprocess.call() gives you little feedback.

I prefer to use subprocess.check_output() so you can analyse what was printed to stdout:

 import subprocess
 res = subprocess.check_output(["sudo", "apt", "update"])
 for line in res.splitlines():
     # process the output line by line

check_output throws an error on on-zero exit of the invoked command

Please note that this doesn't invoke bash or another shell if you don't specify the shell keyword argument to the function (the same is true for subprocess.call(), and you shouldn't if not necessary as it imposes a security hazard), it directly invokes the command.

If you find yourself doing a lot of (different) command invocations from Python, you might want to look at plumbum. With that you can do the (IMO) more readable:

from plumbum.cmd import sudo, apt

res = sudo[apt["update"]]()
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up vote 4 down vote

The subprocess module is designed to do this:

import subprocess
subprocess.call(["sudo", "apt", "update"])

If you would like the script to terminate if the command fails, you might consider using check_call() instead of parsing the return code yourself:

subprocess.check_call(["sudo", "apt", "update"])
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this gave me the following traceback : Traceback (most recent call last): File "/home/Dremor/test.py", line 3, in <module> subprocess.call('sudo', 'yum', 'update') File "/usr/lib64/python3.4/subprocess.py", line 537, in call with Popen(*popenargs, **kwargs) as p: File "/usr/lib64/python3.4/subprocess.py", line 767, in __init__ raise TypeError("bufsize must be an integer") TypeError: bufsize must be an integer (I'm using yum as I'm using Fedora as main OS) – Dremor Mar 16 '15 at 16:07
2  
You forgot the square brackets – Milind Dumbare Mar 16 '15 at 16:19
1  
Also note that subprocess.call() is blocking while subprocess.Popen() is non-blocking.. – heemayl Mar 16 '15 at 18:02
up vote 2 down vote

It is possible you use the bash as a program, with the parameter -c for execute the commands:

Example:

bashCommand = "sudo apt update"
output = subprocess.check_output(['bash','-c', bashCommand])
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