dev_test.py

import datetime

[[datetime.datetime(2015, 10, 28, 0, 34),
  datetime.datetime(2015, 8, 10, 22, 56),
  datetime.datetime(2011, 12, 15, 13, 13),
  datetime.datetime(2004, 6, 21, 10, 44),
  datetime.datetime(2004, 3, 21, 16, 27),
  datetime.datetime(2000, 12, 20, 6, 38)],
 [datetime.datetime(2014, 2, 16, 11, 4),
  datetime.datetime(2012, 3, 4, 5, 45),
  datetime.datetime(2011, 5, 21, 4, 25),
  datetime.datetime(2010, 10, 3, 5, 21),
  datetime.datetime(2004, 8, 2, 9, 50),
  datetime.datetime(2003, 3, 5, 9, 35),
  datetime.datetime(2002, 8, 9, 20, 6),
  datetime.datetime(2002, 5, 5, 11, 38),
  datetime.datetime(2001, 8, 17, 22, 15),
  datetime.datetime(2001, 2, 8, 22, 54),
  datetime.datetime(2000, 9, 8, 14, 8),
  datetime.datetime(2000, 1, 12, 13, 50)],
 [datetime.datetime(2016, 4, 19, 7, 41),
  datetime.datetime(2015, 2, 5, 15, 35),
  datetime.datetime(2013, 3, 19, 6, 4),
  datetime.datetime(2010, 12, 15, 2, 32),
  datetime.datetime(2008, 6, 15, 7, 35),
  datetime.datetime(2006, 1, 19, 0, 38),
  datetime.datetime(2004, 12, 28, 16, 43),
  datetime.datetime(2001, 12, 3, 0, 21),
  datetime.datetime(2000, 6, 11, 3, 54)]]

Output = [
  datetime.datetime(2016, 4, 19, 7, 41),
  datetime.datetime(2015, 10, 28, 0, 34),
  datetime.datetime(2015, 8, 10, 22, 56),
  datetime.datetime(2013, 3, 19, 6, 4),
  datetime.datetime(2012, 3, 4, 5, 45),
  datetime.datetime(2011, 12, 15, 13, 13),
  datetime.datetime(2010, 12, 15, 2, 32),
  datetime.datetime(2008, 6, 15, 7, 35),
  datetime.datetime(2006, 1, 19, 0, 38),
    datetime.datetime(2004, 8, 2, 9, 50)
]

def combine_search_results_by_date(sources, number_of_results):
  """
  Combines the results from several sources in to a single list of results ordered by date.

  Keyword arguments:
  sources -- a list of results from each sources. Each source is an array of datetimes
  """
  pass