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How to convert output from Python after sudo command from <type> int to <type> str?

I have the following code to receive list of process with sudo:
sudoPass = 'mypass'
command = "launchctl list | grep -v com.apple"
x = os.system('echo %s|sudo -S %s' % (sudoPass, command))
But, I receive answer in int. I need in str. Is it possible to convert it to str without loosing data?

os.system returns (in most cases, see https://docs.python.org/3/library/os.html#os.system) the exit value of the process. Meaning most of the time 0 is everything went fine.
What you look for is the subprocess module (https://docs.python.org/3/library/subprocess.html) that allow you to capture output like so :
import subprocess
sudoPass = 'mypass\n' #Note the new line
command = "launchctl list | grep -v com.apple"
x = subprocess.Popen('echo %s|sudo -S %s' % (sudoPass, command), stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
stdout, stderr = x.communicate()
print(stdout)

run cmake command via subprocess.Popen or subprocess.run [duplicate]

If I run echo a; echo b in bash the result will be that both commands are run. However if I use subprocess then the first command is run, printing out the whole of the rest of the line.
The code below echos a; echo b instead of a b, how do I get it to run both commands?
import subprocess, shlex
def subprocess_cmd(command):
process = subprocess.Popen(shlex.split(command), stdout=subprocess.PIPE)
proc_stdout = process.communicate()[0].strip()
print proc_stdout
subprocess_cmd("echo a; echo b")

You have to use shell=True in subprocess and no shlex.split:
import subprocess
command = "echo a; echo b"
ret = subprocess.run(command, capture_output=True, shell=True)
# before Python 3.7:
# ret = subprocess.run(command, stdout=subprocess.PIPE, shell=True)
print(ret.stdout.decode())
returns:
a
b

I just stumbled on a situation where I needed to run a bunch of lines of bash code (not separated with semicolons) from within python. In this scenario the proposed solutions do not help. One approach would be to save a file and then run it with Popen, but it wasn't possible in my situation.
What I ended up doing is something like:
commands = '''
echo "a"
echo "b"
echo "c"
echo "d"
'''
process = subprocess.Popen('/bin/bash', stdin=subprocess.PIPE, stdout=subprocess.PIPE)
out, err = process.communicate(commands)
print out
So I first create the child bash process and after I tell it what to execute. This approach removes the limitations of passing the command directly to the Popen constructor.

Join commands with "&&".
os.system('echo a > outputa.txt && echo b > outputb.txt')

If you're only running the commands in one shot then you can just use subprocess.check_output convenience function:
def subprocess_cmd(command):
output = subprocess.check_output(command, shell=True)
print output

>>> command = "echo a; echo b"
>>> shlex.split(command);
['echo', 'a; echo', 'b']
so, the problem is shlex module do not handle ";"

Got errors like when I used capture_output=True
TypeError: __init__() got an unexpected keyword argument 'capture_output'
After made changes like as below and its works fine
import subprocess
command = '''ls'''
result = subprocess.run(command, stdout=subprocess.PIPE,shell=True)
print(result.stdout.splitlines())

import subprocess
cmd = "vsish -e ls /vmkModules/lsom/disks/ | cut -d '/' -f 1 | while read diskID ; do echo $diskID; vsish -e cat /vmkModules/lsom/disks/$diskID/virstoStats | grep -iE 'Delete pending |trims currently queued' ; echo '====================' ;done ;"
def subprocess_cmd(command):
process = subprocess.Popen(command,stdout=subprocess.PIPE, shell=True)
proc_stdout = process.communicate()[0].strip()
for line in proc_stdout.decode().split('\n'):
print (line)
subprocess_cmd(cmd)

How to execute awk command inside python

I am trying to run the following awk command inside python but I get a syntax error related to the quotes:
import subprocess
COMMAND = "df /dev/sda1 | awk /'NR==2 {sub("%","",$5); if ($5 >= 80) {printf "Warning! Space usage is %d%%", $5}}"
subprocess.call(COMMAND, shell=True)
I tried to escape the quotes but I am still getting the same error.

You may want to put ''' or """ around the string since you have both ' and ".
import subprocess
COMMAND = '''"df /dev/sda1 | awk /'NR==2 {sub("%","",$5); if ($5 >= 80) {printf "Warning! Space usage is %d%%", $5}}"'''
subprocess.call(COMMAND, shell=True)
There also seems to be a relevant answer already for this as well: awk commands within python script

Try this:
import subprocess
COMMAND="df /dev/sda1 | awk 'NR==2 {sub(\"%\",\"\",$5); if ($5 >= 80) {printf \"Warning! Space usage is %d%%\", $5}}'"
subprocess.Popen(COMMAND,stdin=subprocess.PIPE,stdout=subprocess.PIPE, shell=True).stdout.read()

I was writing a python script for my deployment purpose and one part of the script was to explicitely kill the process if its not stopped successfully.
Below is the python code which actually performs
Find the processId of the process named myApplication
ps -ef | grep myApplication | grep -v grep | awk {'print $2'}
and then perform
kill -9 PID //where PID is output of earlier command
import subprocess
import signal
def killApplicationProcessIfStillRunning(app_name):
p1 = subprocess.Popen(['ps', '-ef'], stdout=subprocess.PIPE)
p2 = subprocess.Popen(['grep', app_name],stdin=p1.stdout, stdout=subprocess.PIPE)
p3 = subprocess.Popen(['grep', '-v' , 'grep'],stdin=p2.stdout, stdout=subprocess.PIPE)
p4 = subprocess.Popen(['awk', '{print $2}'],stdin=p3.stdout, stdout=subprocess.PIPE)
out, err = p4.communicate()
if out:
print 'Attempting to kill '+app_name +' process with PID ' +out.splitlines()[0]
os.kill(int(out.splitlines()[0]),signal.SIGKILL)
Now invoke the above method as
killApplicationProcessIfStillRunning(myApplication)
Hope it helps someone.

Best way to execute 'ls' shell command with multiple arguments?

I have the following command that I want to execute in Python and store in a variable:
ls -1 var1 2>/dev/null | grep var2 | grep var3 | head -n 1
But I can't get it to work. I tried using subprocess (both 'call' and 'check_output' as well as 'os.system' and nothing worked.. It always gave me an error or a wrong input, while when I execute this command in the shell it works properly.

For executing shell commands you'd use the subprocess module.
Usage and examples can be found at:
Python Docs: subprocess
The actual python code for calling bash would look like this
import subprocess
task = subprocess.Popen("ls -1 var1 2>/dev/null | grep var2 | grep var3 | head -n 1",
shell=True,
stdout=subprocess.PIPE)
directory = task.stdout.read()
print(directory) # result
The recommended way though would to use python to do the directory search.
Python listdir()
The command for oslistdir could look like this
files = [f for f in os.listdir('.') if re.match(r'[0-9]+.*\.jpg', f)]

I don't have any problem when using subprocess :
>>> import subprocess
>>> sub = subprocess.Popen("ls -1 var1 2>/dev/null | grep var2 | grep var3 | head -n 1", shell=True, stdout=subprocess.PIPE)
>>> str = sub.stdout.read()
>>> str
''
You can find additional informations regarding calling shell command while saving the output here.
Hope it'll be helpful.

You need to ensure you are executing in a shell, as you are relying on the shell to dispatch the pipes, e.g. (Py>3.1):
import subprocess
var1, var2, var3 = "var1", "var2", "var3"
cmd = "ls -1 {} 2>/dev/null | grep {} | grep {} | head -n 1".format(var1, var2, var3)
result = subprocess.check_output(cmd, shell=True)

running bash command from python shell

I want to run a bash command from python shell.
my bash is:
grep -Po "(?<=<cite>).*?(?=</cite>)" /tmp/file1.txt | awk -F/ '{print $1}' | awk '!x[$0]++' > /tmp/file2.txt
what I tried is:
#!/usr/bin/python
import commands
commands.getoutput('grep ' + '-Po ' + '\"\(?<=<dev>\).*?\(?=</dev>\)\" ' + '/tmp/file.txt ' + '| ' + 'awk \'!x[$0]++\' ' + '> ' + '/tmp/file2.txt')
But I don't have any result.
Thank you

If you want to avoid splitting your arguments and worrying about pipes, you can use the shell=True option:
cmd = "grep -Po \"(?<=<dev>).*?(?=</dev>)\" /tmp/file.txt | awk -F/ '{print $1}' | awk '!x[$0]++' > file2.txt"
out = subprocess.check_output(cmd, shell=True)
This will run a subshell which will understands all your directives, including "|" for piping, ">" for redirection. If you do not do this, these symbols normally parsed by the shell will just be passed to grep program.
Otherwise, you have to create the pipes yourself. For example (untested code below):
grep_p = subprocess.Popen(["grep", "-Po", "(?<=<dev>).*?(?=</dev>)", "/tmp/file.txt"], stdout=subprocess.PIPE)
awk_p = subprocess.Popen(["awk", "-F/", "'{print $1}'"], stdin = grep_p.stdout)
file2_fh = open("file2.txt", "w")
awk_p_2 = subprocess.Popen(["awk", "!x[$0]++", stdout = file2_fh, stdin = awk_p.stdout)
awk_p_2.communicate()
However, you're missing the point of python if you are doing this. You should instead look into the re module: re.match, re.sub, re.search, though I'm not familiar enough with awk to translate your commands.

The recommend way to run system commands in python is to use the module subprocess.
import subprocess
a=['grep' ,'-Po', '"(?<=<dev>).*?(?=</dev>)"','/tmp/file.txt']
b=['awk', '-F/', '"{print $1}"']
c=["awk", '"!x[$0]++"']
p1 = subprocess.Popen(a,stdout=subprocess.PIPE)
p2 = subprocess.Popen(b,stdin=p1.stdout,stdout=subprocess.PIPE)
p3 = subprocess.Popen(c,stdin=p2.stdout,stdout=subprocess.PIPE)
p1.stdout.close()
p2.stdout.close()
out,err=p3.communicate()
print out
The point of creating pipes between each subprocess is for security and debugging reasons. Also it makes the code much clearer in terms, which process gets input and sends output to.

Let us write a simple function to easily deal with these messy pipes for us:
def subprocess_pipes (pipes, last_pipe_out = None):
import subprocess
from subprocess import PIPE
last_p = None
for cmd in pipes:
out_pipe = PIPE if not (cmd==pipes[-1] and last_pipe_out) else open(last_pipe_out, "w")
cmd = cmd if isinstance(cmd, list) else cmd.split(" ")
in_pipe = last_p.stdout if last_p else None
p = subprocess.Popen(cmd, stdout = out_pipe, stdin = in_pipe)
last_p = p
comm = last_p.communicate()
return comm
Then we run,
subprocess_pipes(("ps ax", "grep python"), last_pipe_out = "test.out.2")
The result is a "test.out.2" file with the contents of piping "ps ax" into "grep python".
In your case,
a = ["grep", "-Po", "(?<=<cite>).*?(?=</cite>)", "/tmp/file1.txt"]
b = ["awk", "-F/", "{print $1}"]
c = ["awk", "!x[$0]++"]
subprocess_pipes((a, b, c), last_pipe_out = "/tmp/file2.txt")

The commands module is obsolete now.
If you don't actually need the output of your command you can use
import os
exit_status = os.system("your-command")
Otherwise you can use
import suproccess
out, err = subprocess.Popen("your | commands", stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell = True).communicate()
Note: for your command you send stdout to file2.txt so I wouldn't expect to see anything in out you will however still see error messages on stderr which will go into err

you must use
import os
os.system(command)

I think what you are looking for is something like:
ubprocess.check_output(same as popen arguments, **kwargs) , use it the same way you would use a popen command , it should show you the output of the program that's being called.
For more details here is a link: http://freefilesdl.com/how-to-call-a-shell-command-from-python/