code: def date_key(cls, month_string):
  		
  		month, year = month_string.split(',')
  		month_ord = cls.month_ordinal[month]
  		return year, month_ord
docs: Return a key suitable for sorting by month.
  
  		>>> k1 = ChannelPage.date_key('September, 2012')
  		>>> k2 = ChannelPage.date_key('August, 2013')
  		>>> k2 > k1
  		True