如何一次对字典或列表中的所有嵌套字典和列表进行排序?
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【中文标题】如何一次对字典或列表中的所有嵌套字典和列表进行排序?【英文标题】:How to sort all the nested dictionaries and lists inside a dictionary or list at once? 【发布时间】:2021-11-01 04:56:57 【问题描述】:我正试图为此目的开发最有效/最全面的功能:
对字典或列表中的每个嵌套字典或列表进行排序。
注意:我使用 collections.OrderedDict
是因为我想让它也适用于 3.7 之前的 python 版本,即那些不保留字典顺序的版本。
基于来自this thread 的递归函数,它只对嵌套字典进行排序,我正在尝试构建一个对应的递归函数,它只对嵌套列表进行排序,然后通过使用 if 循环来组合它们,以确定对象是否被排序的是字典或列表。
这是我开发的:
from collections import OrderedDict
def recursively_order_dict(d):
ordered_dict = OrderedDict()
for key in sorted(d.keys()):
val = d[key]
if isinstance(val, dict):
val = recursively_order_dict(val)
if isinstance(val, list):
val = recursively_order_list(val)
ordered_dict[key] = val
return ordered_dict
def recursively_order_list(l):
ordered_list = []
for element in sorted(l):
if isinstance(element, list):
element = recursively_order_list(element)
if isinstance(element, dict):
element = recursively_order_dict(element)
ordered_list.append(element)
return ordered_list
def order_all_dicts_and_lists_in_iterable(iterable1):
if isinstance(iterable1, dict):
ordered_iterable = recursively_order_dict(iterable1)
if isinstance(iterable1, list):
ordered_iterable = recursively_order_list(iterable1)
else:
print("%s\n is nor a list nor a dictionary.\nIts type is %s." % (iterable1, type(iterable1)) )
return
return ordered_iterable
它适用于许多示例,但不能通过处理字典dict_2
dict_2 =
"key9":"value9",
"key5":"value5",
"key3":
"key3_1":"value3_1",
"key3_5":"value3_5",
"key3_2":[[],"value3_2_1",[] ],
,
"key2":"value2",
"key8":
"key8_1":"value8_1",
"key8_5":
"key8_5_4":["value8_5_b", "value8_5_a", "value8_5_c"],
"key8_5_2":[,"key8_5_2_4_2":"value8_5_2_4_2", "key8_5_2_4_1":"value8_5_2_4_1", "key8_5_2_4_5":"value8_5_2_4_5", "value8_5_2_1",],
,
"key8_2":"value8_2",
,
"key1":"value1",
sorted_dict_2 = order_all_dicts_and_lists_in_iterable(dict_2)
并抛出此错误:
--------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-12-9cbf4414127d> in <module>
----> 1 order_all_dicts_and_lists_in_iterable(dict_2)
<ipython-input-9-352b10801248> in order_all_dicts_and_lists_in_iterable(iterable1)
26
27 if isinstance(iterable1, dict):
---> 28 ordered_iterable = recursively_order_dict(iterable1)
29 if isinstance(iterable1, list):
30 ordered_iterable = order_all_dicts_and_lists_in_iterable(ordered_iterable)
<ipython-input-9-352b10801248> in recursively_order_dict(d)
6 val = d[key]
7 if isinstance(val, dict):
----> 8 val = recursively_order_dict(val)
9 if isinstance(val, list):
10 val = recursively_order_list(val)
<ipython-input-9-352b10801248> in recursively_order_dict(d)
8 val = recursively_order_dict(val)
9 if isinstance(val, list):
---> 10 val = recursively_order_list(val)
11 ordered_dict[key] = val
12 return ordered_dict
<ipython-input-9-352b10801248> in recursively_order_list(l)
14 def recursively_order_list(l):
15 ordered_list = []
---> 16 for element in sorted(l):
17 if isinstance(element, list):
18 element = recursively_order_list(element)
TypeError: '<' not supported between instances of 'str' and 'list'
所以看起来 Python 无法对由字符串/数字和列表/字典组成的可迭代对象进行排序,因为它不知道从列表/字典中获取什么作为比较项。
与字符串/数字相比,我如何更改我的函数以便将列表/字典放在已排序可迭代的末尾/开头?
简而言之,我应该如何改变我的功能,让它把上面的dict_2
变成这个(手工编辑的)sorted_dict_2
?
sorted_dict_2 =
"key1":"value1",
"key2":"value2",
"key3":
"key3_1":"value3_1",
"key3_2":[ [],[],"value3_2_1" ],
"key3_5":"value3_5",
,
"key5":"value5",
"key8":
"key8_1":"value8_1",
"key8_2":"value8_2",
"key8_5":
"key8_5_2":[
,
,
"value8_5_2_1",
"key8_5_2_4_1":"value8_5_2_4_1",
"key8_5_2_4_2":"value8_5_2_4_2",
"key8_5_2_4_5":"value8_5_2_4_5"
,
],
"key8_5_4":["value8_5_a", "value8_5_b", "value8_5_c"],
,
,
"key9":"value9",
【问题讨论】:
我认为如果你不能对你期望的类型施加任何限制,这将是困难的。例如,[ [],[],"value3_2_1" ]
是否也包含数字?这种情况应该怎么处理?
我错过了什么吗?在order_all_dicts_and_lists_in_iterable
内部,第一个if
是if isinstance(iterable1, dict):
,但随后嵌套在内部,您检查if isinstance(iterable1, list):
,但这永远不会是真的......
谢谢胡安帕!我删除了无法访问的分支
【参考方案1】:
因此,基本上,您需要创建一个关键函数,使所有容器的比较比其他任何容器都少。一个方便的值是float('inf')
。但是,由于我们不知道要排序的内容是包含数字还是字符串,所以我们必须将所有内容转换为元组,并手动映射每个字符串的序数值:map(ord, x)
如果您希望容器移到前面,以下是一个示例(所以 negative inf...:
from collections import OrderedDict
def recursively_order_dict(d):
ordered_dict = OrderedDict()
for key in sorted(d.keys()):
val = d[key]
if isinstance(val, dict):
val = recursively_order_dict(val)
if isinstance(val, list):
val = recursively_order_list(val)
ordered_dict[key] = val
return ordered_dict
def _move_containers_to_end(x):
if isinstance(x, (list, dict)):
# to put at the end, use inf, at the start, -inf
return (float('-inf'),)
elif isinstance(x, str):
return tuple(map(ord, x))
else: # assuming we only can get numbers at this point
return (x,)
def recursively_order_list(l):
ordered_list = []
for element in sorted(l, key=_move_containers_to_end):
if isinstance(element, list):
element = recursively_order_list(element)
if isinstance(element, dict):
element = recursively_order_dict(element)
ordered_list.append(element)
return ordered_list
def order_all_dicts_and_lists_in_iterable(iterable1):
if isinstance(iterable1, dict):
ordered_iterable = recursively_order_dict(iterable1)
elif isinstance(iterable1, list):
ordered_iterable = recursively_orded_list(iterable1)
else:
print("%s\n is nor a list nor a dictionary.\nIts type is %s." % (iterable1, type(iterable1)) )
return ordered_iterable
上面的结果是:
OrderedDict([('key1', 'value1'),
('key2', 'value2'),
('key3',
OrderedDict([('key3_1', 'value3_1'),
('key3_2', [[], [], 'value3_2_1']),
('key3_5', 'value3_5')])),
('key5', 'value5'),
('key8',
OrderedDict([('key8_1', 'value8_1'),
('key8_2', 'value8_2'),
('key8_5',
OrderedDict([('key8_5_2',
[OrderedDict(),
OrderedDict([('key8_5_2_4_1',
'value8_5_2_4_1'),
('key8_5_2_4_2',
'value8_5_2_4_2'),
('key8_5_2_4_5',
'value8_5_2_4_5')]),
OrderedDict(),
'value8_5_2_1']),
('key8_5_4',
['value8_5_a',
'value8_5_b',
'value8_5_c'])]))])),
('key9', 'value9')])
注意,您可能想要执行以下操作:
import sys:
if sys.version_info.minor < 7:
OrderedMapping = dict
else:
from collections import OrderedDict as OrderedMapping
然后使用:
ordered_dict = OrderedMapping()
在recursively_order_dict
【讨论】:
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