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