python - 将字典键更新为升序？

Question

我有一本字典:

A = {'cat': {0: {'variable_1': 'xxx', 'variable_2': 'yyy'},
             1: {'variable_1': 'ttt', 'variable_2': 'kkk'}},
     'dog': {0: {'variable_1': 'xxx', 'variable_2': 'ppp'},
             1: {'variable_1': 'qqq', 'variable_2': 'www'}},
     'fox': {0: {'variable_1': 'xxx', 'variable_2': 'zzz'},
             1: {'variable_1': 'yyy', 'variable_2': 'uuu'},
             3: {'variable_1': 'ccc', 'variable_2': 'jjj'}}}

我想让二级key自动提升像这样:

{'cat': {0: {'variable_1': 'xxx', 'variable_2': 'yyy'},
         1: {'variable_1': 'ttt', 'variable_2': 'kkk'}},
 'dog': {2: {'variable_1': 'xxx', 'variable_2': 'ppp'},
         3: {'variable_1': 'qqq', 'variable_2': 'www'}},
 'fox': {4: {'variable_1': 'xxx', 'variable_2': 'zzz'},
         5: {'variable_1': 'yyy', 'variable_2': 'uuu'},
         6: {'variable_1': 'ccc', 'variable_2': 'jjj'}}}

Answer 1

常规词典是无序的，因此您需要使用 OrderedDict .

全局计数器变量可以跟踪条目总数。

sorted函数将获取键/值元组列表并根据键对它们进行排序。

>>> from collections import OrderedDict
>>> A = {'cat': {0: {'variable_1': 'xxx', 'variable_2': 'yyy'},
                 1: {'variable_1': 'ttt', 'variable_2': 'kkk'}},
         'dog': {0: {'variable_1': 'xxx', 'variable_2': 'ppp'},
                 1: {'variable_1': 'qqq', 'variable_2': 'www'}},
         'fox': {0: {'variable_1': 'xxx', 'variable_2': 'zzz'},
                 1: {'variable_1': 'yyy', 'variable_2': 'uuu'},
                 3: {'variable_1': 'ccc', 'variable_2': 'jjj'}}}

>>> OA = OrderedDict()
>>> count = 0
>>> for animal, info in sorted(A.items()):
        OA[animal] = OrderedDict()
        for i, variables in sorted(info.items()):
            OA[animal][count] = variables
            count += 1

>>> OA
OrderedDict([
   ('cat', OrderedDict([(0, {'variable_2': 'yyy', 'variable_1': 'xxx'}), 
                        (1, {'variable_2': 'kkk', 'variable_1': 'ttt'})])),
   ('dog', OrderedDict([(2, {'variable_2': 'ppp', 'variable_1': 'xxx'}), 
                        (3, {'variable_2': 'www', 'variable_1': 'qqq'})])),
   ('fox', OrderedDict([(4, {'variable_2': 'zzz', 'variable_1': 'xxx'}),
                        (5, {'variable_2': 'uuu', 'variable_1': 'yyy'}),
                        (6, {'variable_2': 'jjj', 'variable_1': 'ccc'})]))
])

如果需要，您可以对最里面的变量进行排序，并将它们也存储在 OrderedDict 中。