I wonder how I get the result of a command in python that runs in CMD and save in a variable,

Question

That program drips a IP, would like to pick up the result of that ping that is done on this line

os.system ('ping -n 4 {} '.format(ip))

that opens the CMD and drips the IP, and save to any variable, so you can put it in a file .txt afterward.

import PySimpleGUI
import os

class Tela : 

    def __init__ (self) :
        layout = [
            [PySimpleGUI.Text ('ip'),PySimpleGUI.Input(key='ip')],
            [PySimpleGUI.Button('enviar')]
        ]
        janela = PySimpleGUI.Window('Dados').layout(layout)
        self.button, self.values = janela.Read()

    def iniciar (self):
        print (self.values)
        ip = self.values ['ip']
        os.system ('ping -n 4 {} '.format(ip))
        return '' 


tela1 = Tela()
tela1.iniciar ()

Answer 1

If you want to get the return in the terminal of a system process call use the module subprocess that allows generating new processes connect to the input, output and error Pipes, and get their return codes.

import subprocess

google = 'www.google.com' 
ptSO = '151.101.129.69'
microsoft = '184.26.42.115'


def ping(site):
   #Abre um subprocesso ping usando a sintaxe Linux
   p = subprocess.run(['ping', '-c', '4', site], stdout=subprocess.PIPE)
   #Abre um subprocesso ping usando a sintaxe Windows
   #p = subprocess.run(['ping', '/n', '4', site], stdout=subprocess.PIPE)

   stdout = p.stdout #captura stdout

   #Retorna o texto do terminal se hover erro retorna vazio
   return stdout.decode('UTF-8') if p.returncode == 0 else ''
   #No windows 
   #return stdout.decode('ISO-8859-1') if p.returncode == 0 else ''

print('aguarde...')
# Salva o retorno de alguns pings em uma lista
pings = [ping(google), ping(ptSO), ping(microsoft)]

print('salvando no arquivo...')
# Salva o retorno de alguns pings em um arquivo
with open("pings.txt", "w") as arquivo:
  for p in pings: 
    arquivo.write(f'{p}\n')

print('despejando no console...')
#imprime a lista contento a saída no terminal de alguns pings
for p in pings: print(f'{p}\n')

Test the code in the Repl.it: https://repl.it/repls/SuburbanThoroughLightweightprocess