FC Quest Insert

import os
import shutil
import struct
import textwrap

#Up to 50 characters used in original file (counting the star as 1 character)
INPUT_COL = 3
trans_tbl_fr = (('|',';'),
                ('é','<'),
                ('è','>'),
                ('à','^'),
                ('ê','_'),
                ('ù','+'),
                ('…','...'),
                ('ç','c'),
                ('â','a'),
                ('ä','a'),
                ('î','i'),
                ('ï','i'),
                ('ö','o'),
                ('ô','o'),
                ('ü','u'),
                ('û','u'),
                ('ë','e'),
                ('æ','ae'),
                ('œ','oe'))
trans_tbl_fr = dict((ord(x[0]), x[1]) for x in trans_tbl_fr)

if os.path.isfile('T_QUEST.orig'):
    pass
elif os.path.isfile('T_QUEST._DT'):
    shutil.copy('T_QUEST._DT', 'T_QUEST.orig')
else:
    print('Missing T_QUEST. Place in this tool\'s folder.')
    quit()
if not os.path.isfile('t_quest.tsv'):
    print('Missing input file t_quest.tsv. Place in this tool\'s folder.')
    quit()

inputdata = []
with open('t_quest.tsv', 'r', encoding='utf-8') as f:
    for line in f:
        line = line.split('\t')
        if len(line) < 3:
            print('hit')
            break
        if line[0] != '':
            inputdata.append([])
        if line[1] != '':
            inputdata[-1].append([line[INPUT_COL]])
        else:
            inputdata[-1][-1].append(line[INPUT_COL])

#First 0x12 bytes of each quest are unknown
unknown_data = []
with open('T_QUEST.orig', 'rb') as f:
    filedata = f.read()
ptr_start = 0x0
ptr_end = 0xAE
ptrs = tuple(struct.unpack(
    '<H', filedata[x:x+2])[0] for x in range(ptr_start, ptr_end, 2))
for ptr in reversed(ptrs):
    unknown_data.append(filedata[ptr:ptr + 0x12])

filedata = bytearray(0xAE)
header_ptrs = []
for quest in inputdata:
    header_ptrs.append(len(filedata))
    filedata += unknown_data.pop()
    quest_ptrs_pos = len(filedata)
    quest_ptrs = []
    filedata += bytearray(0x24)
    for s_list in quest:
        quest_ptrs.append(len(filedata))
        s_out = []
        for s in s_list:
            s = s.translate(trans_tbl_fr)
            if s == 'X':
                s_out.append('')
                continue
            if s == '':
                continue
            s_out.append('\x01 '.join(textwrap.wrap(s, 50)))
        filedata += '\x01'.join(s_out).encode('cp932') + b'\x00'
    filedata[quest_ptrs_pos:quest_ptrs_pos + 0x24] = (
        struct.pack('<' + 'H' * 18, *quest_ptrs))
filedata[:0xAE] = struct.pack('<' + 'H' * len(header_ptrs), *header_ptrs)

with open('T_QUEST._DT', 'wb') as f:
    f.write(filedata)