python读取txt文件

import os
keys_file = 'keys_file.txt'
with open(keys_file, 'r', encoding='utf-8') as rfile:
        keys = rfile.readlines()
        for item in keys:
            d = dict(eval(item))
            if str_key != '':
                if d['key'] == str_key:
                    stime = d['stime']
                    etime = d['etime']
                    key = str_key
                    break