Python3：按元組第一個元素中包含的數據戳對元組列表進行排序

Question

我在 python 中使用排序有困難。

基本上，我有一個這樣的列表，其中包含具有字符串和字典的元組。 該字符串是名稱並包含格式為“%Y-%m-%d_%Hh%Mm%Ss”的時間戳

例子：

[
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-12_05h14m58s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-12_05h14m58s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h53m27s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h53m27s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h49m26s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h49m26s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h50m27s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h50m27s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h50m54s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h50m54s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example2_2020-05-11_10h23m09s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example2_2020-05-11_10h23m09s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example2_2020-05-11_10h22m37s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example2_2020-05-11_10h22m37s",
        "type": "snapshot"
      }
    ]
]

我希望根據時間戳對這個列表進行排序，最好是最近的一個是第一個元素。

我一直在嘗試通過 Python 的 sorted() 方法這樣做，但被卡住了。 它可能是正則表達式和 lambda function 的組合，但我還沒有設法讓它工作。 有人可以幫忙嗎？

Answer 1

您在字符串中的同一位置有日期和時間，因此您可以使用切片來獲取它並進行比較，而無需轉換為時間戳。

data = [ ... your data ...] 

for item in data:
    print(item[0][-25:-5])

給

2020-05-12_05h14m58s
2020-05-11_11h53m27s
2020-05-11_11h49m26s
2020-05-11_11h50m27s
2020-05-11_11h50m54s
2020-05-11_10h23m09s
2020-05-11_10h22m37s

所以你可以使用key=切片

data = sorted(data, reverse=True, key=lambda item:item[0][-25:-5])

---

完整示例

data = [
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-12_05h14m58s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-12_05h14m58s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h53m27s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h53m27s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h49m26s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h49m26s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h50m27s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h50m27s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example_2020-05-11_11h50m54s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example_2020-05-11_11h50m54s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example2_2020-05-11_10h23m09s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example2_2020-05-11_10h23m09s",
        "type": "snapshot"
      }
    ],
    [
      "/lfs_store/history/snapshot_stack_instance_document_example2_2020-05-11_10h22m37s.json",
      {
        "category": "history",
        "description": "an example of a document, using the stack_instance type",
        "name": "stack_instance_document_example2_2020-05-11_10h22m37s",
        "type": "snapshot"
      }
    ]
]

#for item in data:
#    print(item[0][-25:-5])

data = sorted(data, reverse=True, key=lambda item:item[0][-25:-5])

print(data)

Answer 2

這是您可以使用的key ：

def date_key(t):
    path, info = t
    date_regex = r"\d{4}-\d{2}-\d{2}_\d{2}h\d{2}m\d{2}s"
    m = re.search(date_regex, path)
    date = m.group(0)
    return date

接着：

xs.sort(key=date_key)