just a rather quick question to ask as I have been looking everywhere but haven't seen something that has worked for me I suppose. Suppose I have a list of tuples where:
data = (a, b, DateTime, d)
I wish to sort the list by dateTime in descending order where the most recent date/time is first. In this case, DateTime is the third element in the list, and I don't seem why my program doesn't sort when I try to sort. Any suggestions on how to sort the hypothetical example above by datetime?
>>> from pprint import pprint
>>> import datetime
>>> l = [('a', 'b', datetime.datetime.now(), 'd') for _ in xrange(10)]
>>> pprint(l)
[('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 349796), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350127), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350132), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350134), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350137), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350140), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350143), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350145), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350148), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350151), 'd')]
>>> l_desc = sorted(l, key=lambda t: t[2], reverse=True)
>>> pprint(l_desc)
[('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350151), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350148), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350145), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350143), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350140), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350137), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350134), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350132), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350127), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 349796), 'd')]
>>> l_asc = sorted(l_desc, key=lambda t: t[2])
>>> pprint(l_asc)
[('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 349796), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350127), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350132), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350134), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350137), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350140), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350143), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350145), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350148), 'd'),
('a', 'b', datetime.datetime(2013, 12, 11, 17, 35, 0, 350151), 'd')]
