Why my tokenize seem not good

My code in like this :

import sentencepiece as spm
import re
s = spm.SentencePieceProcessor(‘jpa_wiki_100000.model’)

path_input_eng = ‘voc-en.txt’
path_output_eng = ‘en_trainv1.txt’

path_input_jyp = ‘voc-ja.txt’
path_output_jyp = ‘jp_trainv1.txt’

def tokenize(sequence):
test = s.Encode(sequence, out_type= str , enable_sampling= True , alpha = 0.001, nbest_size = 2)
sequence_token = ‘’
for j in range(0,len(test)):
test_clean = test[j]
test_clean = test_clean.replace(‘▁’,’’)
if test_clean != ‘’:
sequence_token = sequence_token + ’ ’ + test_clean
return sequence_token

def save_file(path_input, path_output, check_token = False, number_line = 1000):
open_file = open(path_input, ‘r’)
save_file = open(path_output, ‘w’)
for i in range(number_line):
line = open_file.readline()
if check_token == True:
line = tokenize(line)

a = ‘iPhone 6 Plus 7 Plus 8 Plus 8プラス最新の8500mAh外部バッテリパック保護携帯電話充電器用’

And the result is :
iPhone 6 Plus 7 Plus 8 Plus 8プラス最新の8500mAh外部バッテリパック保護携帯電話充電器用
i P h one 6 P lus 7 P lus 8 P lus 8 プラス 最新の 8 5 00 m A h 外部 バッ テリ パック 保護 携帯電話 充電器 用

Its seem its can tokenize the Japanese but the tokenize for English is not good. so How can i fix this? I translate Japanese to English

I had a really quick look, but at first glance did you include both text (English and Japanese) to create your sentence piece model? If you only included japenese fur sure the tokenization of English won’t work well…

i use pretrain model jpa_wiki_100000.model i see online. so what should i do to fix this. Should i go to Sentenpicece and train a new model for my data?

I personally don’t have any experience in using pretained model, yet.

But the model was trained on a specif vocab and you need to use the same vocab.

Does the model come with only 1 sentence piece model? Or are there 2?. You can train a sentencePiece model individualy on target and source or do only 1 model combined.

What is the issue with the tokenization? The tokenizer doesn’t necessarily split on word boundaries.