Translate Onetab txt export → Keptab json import

trans.py

import time, json
from urllib.parse import urlparse, urlunparse

class tab:
    def __init__(self, url, title):
        self.url = url; self.title = title
        self.favIconUrl = urlunparse(urlparse(url)._replace(path='favicon.ico',params='',query='',fragment=''))
        self.pinned = False; self.muted = False

_id, res, tabs, urls = int(time.time() * 1000), [], [], []

lines = open('onetab.txt').readlines()
lines.append('\n')

for ln in lines:
    if ln is '\n':
        _id = _id - 60000
        res.append({
            "_id": _id, "time": _id,
            "title": "", "tags": [],
            "tabs": tabs, "urls": urls,
            "lock": False, "star": False
        })
        tabs, urls = [], []
        continue

    token = ln.strip().split('|', 2)
    url, title = token[0].strip(), '|'.join(token[1:]) 

    t = tab(url, title)
    tabs.append(t.__dict__)
    urls.append(url)

with open('keptab.json', 'w') as f:
    json.dump(res, f)