如何在 python 脚本上运行高级 Linux 命令

Question

I want to get the string output of the following linux command

systemctl show node_exporter |grep LoadState| awk '{split($0,a,"="); print a[2]}'

I tried with

import subprocess
output = subprocess.check_output("systemctl show node_exporter |grep LoadState| awk '{split($0,a,"="); print a[2]}'", shell=True)

but the output is, output = subprocess.check_output("systemctl show node_exporter |grep LoadState| awk '{split($0,a,"="); print a[2]}'", shell=True) SyntaxError: keyword can't be an expression

Answer 1

You need to escape the double quotes (because they indicate the begin/end of the string):

import subprocess
output = subprocess.check_output("systemctl show node_exporter |grep LoadState| awk '{split($0,a,\"=\"); print a[2]}'", shell=True)

Answer 2

Well,

First of all, the function takes a list of strings as a command, not a single string. Eg:

"ls -a -l" - wrong
["ls", "-a", "-l"] - good

Secondly. If the linux command is super complex or contains lots of lines - it makes sense to create a separate bash file eg command.sh, put your linux commands there and run the script from python with:

import subprocess
output = subprocess.check_output(["./command.sh"], shell=True)