code: def _syscall(self, command, input=None, env=None, *params):
          '''
          Call an external system command.
          '''
          return Popen([command] + list(params), stdout=PIPE, stdin=PIPE, stderr=STDOUT,
                       env=env or os.environ).communicate(input=inputf _syscall(self, command, input=None, env=None, *params):
          '''
          Call an external system command.
          '''
          return Popen([command] + list(params), stdout=PIPE, stdin=PIPE, stderr=STDOUT,
                       env=env or os.environ).communicate(input=input)
docs: Call an external system command.