遍历字典列表以查找最新的DateTime

Question

我有一个txt文件和一些包含字典的列表。这就是它的样子：

[]
[]
[{'userId': '61f6b0e2-XXXX-XXXX-XXXX-82440f1b316b', 'lastLogOnDateTime': '2022-04-11T08:11:30.077Z'}]
[{'userId': 'a159ace2-XXXX-XXXX-XXXX-221885ce1282', 'lastLogOnDateTime': '2022-03-01T15:31:42.661Z'}]
[{'userId': '5e2a0b81-XXXX-XXXX-XXXX-4e7ac8d1c0d1', 'lastLogOnDateTime': '2022-04-14T08:25:11.354Z'}]
[{'userId': '75bfd26a-XXXX-XXXX-XXXX-52238cf882ab', 'lastLogOnDateTime': '2022-04-14T10:22:16.466Z'}]
[{'userId': 'ecff3ce3-XXXX-XXXX-XXXX-21a9baa658de', 'lastLogOnDateTime': '2022-01-19T16:00:24.838Z'}]
[{'userId': '5983f74c-XXXX-XXXX-XXXX-6c565edd08cc', 'lastLogOnDateTime': '2022-03-21T12:56:45.099Z'}, {'userId': '865e5246-XXXX-XXXX-XXXX-ef19a8ae4ce7', 'lastLogOnDateTime': '2022-04-14T09:10:07.863Z'}]
[{'userId': '7b2d3af3-XXXX-XXXX-XXXX-8870c5f19287', 'lastLogOnDateTime': '2022-04-14T06:06:38.75Z'}]
[{'userId': 'ecff3ce3-XXXX-XXXX-XXXX-21a9baa658de', 'lastLogOnDateTime': '2022-03-15T12:45:39.116Z'}, {'userId': '6560f0cd-XXXX-XXXX-XXXX-ca0b743734bb', 'lastLogOnDateTime': '2022-04-07T05:04:38.345Z'}, {'userId': '5865d24c-XXXX-XXXX-XXXX-57286e4aeac9', 'lastLogOnDateTime': '2022-04-14T06:54:56.632Z'}]
[{'userId': 'e7b36f37-XXXX-XXXX-XXXX-f6a3b2bff570', 'lastLogOnDateTime': '2021-10-29T14:29:20.445Z'}, {'userId': '5983f74c-XXXX-XXXX-XXXX-6c565edd08cc', 'lastLogOnDateTime': '2021-11-23T12:25:31.788Z'}]
[{'userId': '79a60545-XXXX-XXXX-XXXX-23374487c8e5', 'lastLogOnDateTime': '2022-04-14T09:09:36.33Z'}]
[{'userId': '865e5246-XXXX-XXXX-XXXX-ef19a8ae4ce7', 'lastLogOnDateTime': '2022-03-22T07:36:12.719Z'}]
[{'userId': 'e7b36f37-XXXX-XXXX-XXXX-f6a3b2bff570', 'lastLogOnDateTime': '2021-10-27T08:05:54.091Z'}, {'userId': 'b3169036-XXXX-XXXX-XXXX-50f7c4806fa3', 'lastLogOnDateTime': '2021-11-05T11:01:39.796Z'}]
[{'userId': '5983f74c-XXXX-XXXX-XXXX-6c565edd08cc', 'lastLogOnDateTime': '2021-12-17T14:06:03.918Z'}]

因此，如您所见，一些列表是空的，而另一些则包含多个字典。我不知道的是如何遍历一个列表，然后用最新的DateTime检查字典中的字典。因此，每个列表应该只包含一个字典，这是具有最新DateTime的字典。

例如：

[{'userId': '5983f74c-XXXX-XXXX-XXXX-6c565edd08cc', 'lastLogOnDateTime': '2022-03-21T12:56:45.099Z'}, {'userId': '865e5246-XXXX-XXXX-XXXX-ef19a8ae4ce7', 'lastLogOnDateTime': '2022-04-14T09:10:07.863Z'}]

应成为：

[{'userId': '865e5246-XXXX-XXXX-XXXX-ef19a8ae4ce7', 'lastLogOnDateTime': '2022-04-14T09:10:07.863Z'}]

当然，空的可能仍然是空的。

谢谢!

Answer 1

您可以根据lastLogOnDateTime字段按降序排序列表，只需获取列表的第一个字典即可。

res = []
s = sorted(list_of_dict, key=lambda d: d['lastLogOnDateTime'], reverse=True)
if len(s)>0:
    res = [s[0]]