def update_exchange(exchange):
""" 更新交易所的账号信息 """
accounts = list(Account.query({'exchange': exchange}))
e = Exchange.query_one({'_id': exchange})
for key, value in accounts_summary(accounts).items():
setattr(e, key, value)
e.num_users = len(set(a.user for a in accounts))
e.num_accounts = len(accounts)
e.upsert()