How do I sort a list of date and/or datetime objects? The accepted answer here isn't working for me:
from datetime import datetime,date,timedelta
a=[date.today(), date.today() + timedelta(days=1), date.today() - timedelta(days=1)]
print a # prints '[datetime.date(2013, 1, 22), datetime.date(2013, 1, 23), datetime.date(2013, 1, 21)]'
a = a.sort()
print a # prints 'None'....what???
You're getting None because list.sort() it operates in-place, meaning that it doesn't return anything, but modifies the list itself. You only need to call a.sort() without assigning it to a again.
There is a built in function sorted(), which returns a sorted version of the list - a = sorted(a) will do what you want as well.
Source: Stackoverflow.com