code: def target_to_ipv4_cidr(target):
      
  
      splitted = target.split('/')
      if len(splitted) != 2:
          return None
      try:
          start_packed = inet_pton(socket.AF_INET, splitted[0])
          block = int(splitted[1])
      except (socket.error, ValueError):
          return None
      if block <= 0 or block > 30:
          return None
      start_value = int(binascii.hexlify(start_packed), 16) >> (32 - block)
      start_value = (start_value << (32 - block)) + 1
      end_value = (start_value | (0xffffffff >> block)) - 1
      start_packed = struct.pack('!I', start_value)
      end_packed = struct.pack('!I', end_value)
      return ipv4_range_to_list(start_packed, end_packed)
docs: Attempt to return a IPv4 CIDR list from a target string.