Replies PyCharm and Checkio different with the same source data. Help!
From: https://py.checkio.org/mission/flatten-list/solve/
HTTP_USER_AGENT:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0
Created at: 2016/12/24 00:59; Updated at: 2016/12/27 22:18