oot decomp's ichaindis.py but it outputs (hardcoded) struct member names

ichaindis_membernames.py

#!/usr/bin/python3

import os
import sys
import struct
import argparse

ICHAIN_MACROS = [
    'ICHAIN_U8',
    'ICHAIN_S8',
    'ICHAIN_U16',
    'ICHAIN_S16',
    'ICHAIN_U32',
    'ICHAIN_S32',
    'ICHAIN_F32',
    'ICHAIN_F32_DIV1000',
    'ICHAIN_VEC3F',
    'ICHAIN_VEC3F_DIV1000',
    'ICHAIN_VEC3S',
]

# dictionary mapping offset in Actor struct to the member name
# for example 0 -> id
# generated from the actor struct source with following regex replacement:
# " *\/\* +(0x[0-9a-fA-F]+) +\*\/[^\n;]*[ *]([^ *\n[]+)(?:\[[0-9a-fA-Fx]+\])?;(?: *\/\/[^\n]*)?" -> "\1: '\2',"
# then some substructs were split (PosRot), partly split (ActorShape) or removed (CollisionCheckInfo)
FIELD_NAMES = {
    0x000: 'id',
    0x002: 'type',
    0x003: 'room',
    0x004: 'flags',
    0x008: 'initPosRot.pos',
    0x014: 'initPosRot.rot',
    0x01C: 'params',
    0x01E: 'objBankIndex',
    0x01F: 'unk_1F',
    0x020: 'sfx',
    0x024: 'posRot.pos',
    0x030: 'posRot.rot',
    0x038: 'posRot2.pos',
    0x044: 'posRot2.rot',
    0x04C: 'unk_4C',
    0x050: 'scale',
    0x05C: 'velocity',
    0x068: 'speedXZ',
    0x06C: 'gravity',
    0x070: 'minVelocityY',
    0x074: 'wallPoly',
    0x078: 'floorPoly',
    0x07C: 'wallPolySource',
    0x07D: 'floorPolySource',
    0x07E: 'wallPolyRot',
    0x080: 'groundY',
    0x084: 'waterY',
    0x088: 'bgCheckFlags',
    0x08A: 'yawTowardsLink',
    0x08C: 'xyzDistFromLinkSq',
    0x090: 'xzDistFromLink',
    0x094: 'yDistFromLink',
    0x0B4: 'shape.rot',
    0x0CC: 'unk_CC',
    0x0E4: 'projectedPos',
    0x0F0: 'projectedW',
    0x0F4: 'uncullZoneForward',
    0x0F8: 'uncullZoneScale',
    0x0FC: 'uncullZoneDownward',
    0x100: 'pos4',
    0x10C: 'unk_10C',
    0x10D: 'unk_10D',
    0x10E: 'textId',
    0x110: 'freezeTimer',
    0x112: 'dmgEffectParams',
    0x114: 'dmgEffectTimer',
    0x115: 'isDrawn',
    0x116: 'unk_116',
    0x117: 'naviEnemyId',
    0x118: 'parent',
    0x11C: 'child',
    0x120: 'prev',
    0x124: 'next',
    0x128: 'init',
    0x12C: 'destroy',
    0x130: 'update',
    0x134: 'draw',
    0x138: 'overlayEntry',
}

def main():
    parser = argparse.ArgumentParser(description='Decompiles an InitChain')
    parser.add_argument('filename', help='ROM file path')
    parser.add_argument('offset', help='ROM offset to an InitChain')
    parser.add_argument('--no-names', help='Do not use struct names', action='store_true')
    args = parser.parse_args()
    romOff = int(args.offset, 16)

    try:
        with open(args.filename, 'rb') as f:
            romData = f.read()
    except IOError:
        print('failed to read file ' + args.filename)
        sys.exit(1)

    print ('static InitChainEntry sInitChain[] = {')
    while True:
        entry = struct.unpack('>I', romData[romOff:romOff+4])[0]
        romOff += 4

        cont = entry >> 31
        t = (entry >> 27) & 0xF
        offset = ((entry) >> 16) & 0x7FF
        value = (entry) & 0xFFFF

        field_name = None
        if not args.no_names:
            field_name = FIELD_NAMES.get(offset)
        if field_name is None:
            field_name = 'unk_{:X}'.format(offset)

        print('    {0}({1}, {2}, {3}),'.format(ICHAIN_MACROS[t], field_name, value, ('ICHAIN_CONTINUE' if cont == 1 else 'ICHAIN_STOP')))
        if cont == 0:
            break
    print ('};')

if __name__ == "__main__":
    main()