I would like to give some feedback about ...

From: http://www.checkio.org/mission/median/solve/

HTTP_USER_AGENT:

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:33.0) Gecko/20100101 Firefox/33.0

The median is not 3 in that tuple, its 2
assert checkio([3, 1, 2, 5, 3]) == 3, "Not sorted list"