Run command in CMD via python and extract the data

Question

I am trying to use the below code to run a command and extract the data from the cmd.

the file with the commands and data is a txt file. (let me know if I should change it or use an excel if better).

the commands look something like this: ping "host name" which would result in some data in the cmd.there is list of these in the file. so it would ping "hostname1" then line two ping "hostname2"..etc

THE QUESTION: I want it to run every line individually and extract the results from the cmd and store them in a txt file or excel file – Ideally I want all the results in the same file. is this possible? and how?

here is the code so far:

root_dir = pathlib.Path(r"path to file here")
cmds_file = root_dir.joinpath('actual file here with commands and data') 
#fail = []
cmds = cmds_file.read_text().splitlines()

try:

for cmd in cmds:
    args = cmd.split() 
    print(f"nRunning: {args[0]}")
    output = subprocess.check_output(args)


    print(output.decode("utf-8"))
    out_file = root_dir.joinpath(f"Name of file where I want results printed in")
    out_file.write_text(output.decode("utf-8"))
except:
pass

Asked By: JuniorData

||

Source

Answer 1

You can use a module called subprocess import subprocess

Then you can define a variable like this
run = subprocess.run(command_to_execute, capture_output=True)

After that you can do print(run.stdout) to print the command output.
If you want to write it to a file you can do this after you run the above code

    with open("PATH TO YOUR FILE", "w") as file:
        file.write(run.stdout)

This should write a file which contains the output of your command
After that close the file using file.close() and reopen it but in "a" mode

    with open("PATH TO YOUR FILE", "a") as file:
        file.write(n + run.stdout)

This should append data to your file.
Remember to close the file just for best practice, I have some bad memorys about not closing the file after I opened it 😀

Answered By: Teer 2008

Answer 2

My plan is simple:

Open input, output file
Read input file line by line
Execute the command and direct the output to the output file

#!/usr/bin/env python3
import pathlib
import shlex
import subprocess

cmds_file = pathlib.Path(__file__).with_name("cmds.txt")
output_file = pathlib.Path(__file__).with_name("out.txt")
with open(cmds_file, encoding="utf-8") as commands, open(output_file, "w", encoding="utf-8") as output:
    for command in commands:
        command = shlex.split(command)
        output.write(f"n# {shlex.join(command)}n")
        output.flush()
        subprocess.run(command, stdout=output, stderr=subprocess.STDOUT, encoding="utf-8")

Notes

Use shlex.split() to simulate the bash shell’s command split
The line output.write(...) is optional. You can remove it
With subprocess.run(...), the stdout=output will redirect the command’s output to the file. You don’t have to do anything.

Update

I updated the subprocess.run line to redirect stderr to stdout, so error will show.

Answered By: Hai Vu

Run command in CMD via python and extract the data

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