Example of Monero's /get_o_indexes.bin RPC in Python

get_o_indexes.py

import requests
import struct

def get_o_indexes():
  tx_hex = "942eaeb8ba05bd13e8d7b85f1599b52a808263419e680d2d1e32ed2f58f6cb78"
  tx_bin_len = 32

  # Portable storage signature and version
  signature = 0x0111010101010201
  version = 1

  # Signature and version
  req_data =  struct.pack("> Q B", signature, version)
  # Entry count, entry name length, entry name
  req_data += struct.pack("< B B 4s", 1 << 2, 4, "txid")
  # Entry value type (here a char array), entry value length (as varint)
  req_data += struct.pack("< B B", 10, tx_bin_len << 2)
  # Entry value data
  req_data += bytearray.fromhex(tx_hex)

  print
  print "Calling /get_o_indexes.bin with:"
  print "  txid", ":",  tx_hex
  print

  res = requests.post('http://localhost:18081/get_o_indexes.bin', data=req_data)

  if res.status_code != 200:
    print "Response status code:", res.status_code
    return

  # Everything that follows is a crude parsing of the response.

  print "Parsed response:"

  # First read & check the signatures and versions match...
  buf = buffer(res.content)
  offset = 0
  res_signature, res_version  = struct.unpack_from("> Q B", buf, offset)
  offset = 10
  if res_signature != signature:
    print "  Signature incorrect. Aborting."
    return
  if res_version != version:
    print "  Version incorrect. Aborting."
    return

  # Now read and parse each response field...
  while offset < len(res.content):
    field_len, = struct.unpack_from("< B", buf, offset)
    offset += 1
    field_name, = struct.unpack_from(str(field_len)+"s", buf, offset)
    offset += field_len
    field_type, = struct.unpack_from("< B", buf, offset)
    offset += 1
    if field_type == 0x85: # uint64_t array
      arr_len, = struct.unpack_from("< B", buf, offset)
      offset += 1
      arr_len = arr_len >> 2
      items = struct.unpack_from("< "+str(arr_len)+"Q", buf, offset)
      offset += arr_len * 8
      print " ", field_name, ":", items
    elif field_type == 0x0A: # char array
      str_len, = struct.unpack_from("< B", buf, offset)
      offset += 1
      str_len = str_len >> 2 # Being lazy as not checking with the mask!!!
      item, = struct.unpack_from(str(str_len)+"s", buf, offset)
      offset += str_len
      print " ", field_name, ":", item
    elif field_type == 0x0B: # bool
      item, = struct.unpack_from("< ?", buf, offset)
      offset += 1
      print " ", field_name, ":", item
    else:
      print "  Field type", hex(field_type), "not yet implemented. Aborting."
      break


if __name__ == "__main__":
  get_o_indexes()