code: def check_command(self, command):
          
  
          # Use `command` to see if command is callable, store exit code
          code = os.system("command -v {0} >/dev/null 2>&1 || {{ exit 1; }}".format(command))
  
          # If exit code is not 0, report which command failed and return False, else return True
          if code != 0:
              print("Command is not callable: {0}".format(command))
              return False
          else:
              return True
docs: Check if command can be called.