‘‘‘[    {‘symbol‘: 101, ‘sort‘: 1, ‘name‘: ‘aaaa‘},    {‘symbol‘: 102, ‘sort‘: 2, ‘name‘: ‘bbbb‘},    {‘symbol‘: 103, ‘sort‘: 3, ‘name‘: ‘cccc‘},    {‘symbol‘: 104, ‘sort‘: 4, ‘name‘: ‘dddd‘},    {‘symbol‘: 105, ‘sort‘: 5, ‘name‘: ‘eeee‘},    {‘symbol‘: 106, ‘sort‘: 6, ‘name‘: ‘ffff‘},    {‘symbol‘: 107, ‘sort‘: 7, ‘name‘: ‘gggg‘},    {‘symbol‘: 108, ‘sort‘: 8, ‘name‘: ‘hhhh‘},    {‘symbol‘: 109, ‘sort‘: 9, ‘name‘: ‘iiii‘}]转换成如下的结构，便于通过ID获取记录值{    101: {‘sort‘: 1, ‘symbol‘: 101, ‘name‘: ‘aaaa‘},    102: {‘sort‘: 2, ‘symbol‘: 102, ‘name‘: ‘bbbb‘},    103: {‘sort‘: 3, ‘symbol‘: 103, ‘name‘: ‘cccc‘},    104: {‘sort‘: 4, ‘symbol‘: 104, ‘name‘: ‘dddd‘},    105: {‘sort‘: 5, ‘symbol‘: 105, ‘name‘: ‘eeee‘},    106: {‘sort‘: 6, ‘symbol‘: 106, ‘name‘: ‘ffff‘},    107: {‘sort‘: 7, ‘symbol‘: 107, ‘name‘: ‘gggg‘},    108: {‘sort‘: 8, ‘symbol‘: 108, ‘name‘: ‘hhhh‘},    109: {‘sort‘: 9, ‘symbol‘: 109, ‘name‘: ‘iiii‘}}‘‘‘students = [        {‘symbol‘: 101, ‘sort‘: 1, ‘name‘: ‘aaaa‘},        {‘symbol‘: 102, ‘sort‘: 2, ‘name‘: ‘bbbb‘},        {‘symbol‘: 103, ‘sort‘: 3, ‘name‘: ‘cccc‘},        {‘symbol‘: 104, ‘sort‘: 4, ‘name‘: ‘dddd‘},        {‘symbol‘: 105, ‘sort‘: 5, ‘name‘: ‘eeee‘},        {‘symbol‘: 106, ‘sort‘: 6, ‘name‘: ‘ffff‘},        {‘symbol‘: 107, ‘sort‘: 7, ‘name‘: ‘gggg‘},        {‘symbol‘: 108, ‘sort‘: 8, ‘name‘: ‘hhhh‘},        {‘symbol‘: 109, ‘sort‘: 9, ‘name‘: ‘iiii‘}    ] symbol_list = map(lambda x: (x.get(‘symbol‘), x), students)print symbol_listprint ‘-----------------------------------------‘print dict(symbol_list)#value_list = map(lambda x: x, students)###print dict(zip(symbol_list, value_list))###student = {#        101: {‘symbol‘: 101, ‘sort‘: 1, ‘name‘: ‘aaaa‘}#        }##student = [#        {101: {‘symbol‘: 101, ‘sort‘: 1, ‘name‘: ‘aaaa‘}}#        ]#排序用法：students = [            {‘name‘:‘zhangsan‘, ‘price‘:20.01, ‘date‘:‘2015-01-09T01:00:00Z‘},            {‘name‘:‘lisi‘, ‘price‘:10.01, ‘date‘:‘2013-01-09T01:00:00Z‘},            {‘name‘:‘wangwu‘, ‘price‘:0.01, ‘date‘:‘2012-01-09T01:00:00Z‘}]  print sorted(students, key=lambda s:s["name"])print sorted(students, key=lambda s:s["price"], reverse=True)print sorted(students, key=lambda s:s["date"],  reverse=True)aa = sorted(students, key=lambda s:s["price"], reverse=True)sorted(aa, key=lambda s:s["date"],  reverse=True)symbol_arr = [<Symbol: Symbol object>, <Symbol: Symbol object>, <Symbol: Symbol object>] sorted(symbol_arr, key=lambda s:s.amount, reverse=True)