code: def operating_system():
      
      if platform.system() == 'Darwin':
          return 'OS X Version %s' % platform.mac_ver()[0]
      distribution = ' '.join(platform.linux_distribution()).strip()
      os_platform = platform.platform(True, True)
      if distribution:
          os_platform += ' (%s)' % distribution
      return os_platform
docs: Return a string identifying the operating system the application
      is running on.
  
      :rtype: str