nodes: 0, module; 1, function_definition; 2, function_name:date_key; 3, parameters; 4, block; 5, identifier:cls; 6, identifier:month_string; 7, expression_statement; 8, expression_statement; 9, expression_statement; 10, return_statement; 11, comment:"""
  		Return a key suitable for sorting by month.
  
  		>>> k1 = ChannelPage.date_key('September, 2012')
  		>>> k2 = ChannelPage.date_key('August, 2013')
  		>>> k2 > k1
  		True
  		"""; 12, assignment; 13, assignment; 14, expression_list; 15, pattern_list; 16, call; 17, identifier:month_ord; 18, subscript; 19, identifier:year; 20, identifier:month_ord; 21, identifier:month; 22, identifier:year; 23, attribute; 24, argument_list; 25, attribute; 26, identifier:month; 27, identifier:month_string; 28, identifier:split; 29, string; 30, identifier:cls; 31, identifier:month_ordinal; 32, string_content:,
code: def date_key(cls, month_string):
  		"""
  		Return a key suitable for sorting by month.
  
  		>>> k1 = ChannelPage.date_key('September, 2012')
  		>>> k2 = ChannelPage.date_key('August, 2013')
  		>>> k2 > k1
  		True
  		"""
  		month, year = month_string.split(',')
  		month_ord = cls.month_ordinal[month]
  		return year, month_ord