按值查找嵌套字典路徑

我正在使用遞回從嵌套的 JSON 中找到一些特定值的樹路徑。例如，在給定的 JSON 上，我試圖找到src元素的完整路徑樹。注意我有 2 個具有相同值的 src 元素，我當前的代碼適用于不同的src值，但是當我的src鍵具有相同的值時，結果不是預期的。

當前的 JSON：

{
  "imagepanel": {
    "image": [
      {
        "scaled_image": {
          "classes": "w-full",
          "aspect_ratios": "frame sm:4:3 xmed:4:3",
          "art_directions": [
            {
              "alt": "River waves",
              "src": "path/to/file/53339c03d67e6ee5-lesson-3.jpg",
              "type": "jpg",
              "media": "(min-width:900.1px)",
              "sizes": "50vw",
              "intrinsicwidth": "1411",
              "intrinsicheight": "1000"
            },
            {
              "alt": "River waves",
              "src": "path/to/file/53339c03d67e6ee5-lesson-3.jpg",
              "type": "jpg",
              "media": "(max-width:900px)",
              "sizes": "100vw",
              "intrinsicwidth": "0",
              "intrinsicheight": "0"
            }
          ]
        }
      }
    ],
    "title": "<p><span class=\"drop-cap\" drop-cap=\"true\">WHAT TO WATCH</span></p>",
    "cta_label": "SEE THE LIST",
    "left_image": true
  }
}

當前代碼：

import json
import pprint
def breadcrumb_finder(json_dict_or_list, value):
    if json_dict_or_list == value:
        return [json_dict_or_list]
    elif isinstance(json_dict_or_list, dict):
        for k, v in json_dict_or_list.items():
            child = breadcrumb_finder(v, value)
            if child:
                return [k]   child
    elif isinstance(json_dict_or_list, list):
        lst = json_dict_or_list
        for i in range(len(lst)):
            child = breadcrumb_finder(lst[i], value)
            if child:
                return [str(i)]   child

data = r'''{"imagepanel":{"image":[{"scaled_image":{"classes":"w-full","aspect_ratios":"frame sm:4:3 xmed:4:3","art_directions":[{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(min-width:900.1px)","sizes":"50vw","intrinsicwidth":"1411","intrinsicheight":"1000"},{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(max-width:900px)","sizes":"100vw","intrinsicwidth":"0","intrinsicheight":"0"}]}}],"title":"<p><span class=\"drop-cap\" drop-cap=\"true\">WHAT TO WATCH</span></p>","cta_label":"SEE THE LIST","left_image":true}}'''
data = json.loads(data)

all_src = ['path/to/file/53339c03d67e6ee5-lesson-3.jpg', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']
for src in all_src:
    nested_path = breadcrumb_finder(data, src)
    print(nested_path)

電流輸出：

['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '0', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']
['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '0', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']

                                                               ^^^ note index here

預期輸出：

['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '0', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']
['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '1', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']

                                                               ^^^ note index here

uj5u.com熱心網友回復：

經過一番除錯后，我注意到問題出在這段代碼中：

elif isinstance(json_dict_or_list, list):
    lst = json_dict_or_list
    for i in range(len(lst)):
        child = breadcrumb_finder(lst[i], value)
        if child:
            return [str(i)]   child

由于您在child陣列不為空時呼叫 return ，因此lst[i]如果滿足條件，它也會忽略之后的所有元素。

因此，我通過使用回溯稍微更改了您的代碼：

import json
import pprint
results = []
def breadcrumb_finder(json_dict_or_list, value, path, result):
    if json_dict_or_list == value:
        path.append(json_dict_or_list)
        result.append(path.copy())
        path.pop()
    elif isinstance(json_dict_or_list, dict):
        for k, v in json_dict_or_list.items():
            path.append(k)
            child = breadcrumb_finder(v, value, path, result)
            path.pop()
                
    elif isinstance(json_dict_or_list, list):
        lst = json_dict_or_list
        for i in range(len(lst)):
            path.append(i)
            child = breadcrumb_finder(lst[i], value, path, result)
            path.pop()       

data = r'''{"imagepanel":{"image":[{"scaled_image":{"classes":"w-full","aspect_ratios":"frame sm:4:3 xmed:4:3","art_directions":[{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(min-width:900.1px)","sizes":"50vw","intrinsicwidth":"1411","intrinsicheight":"1000"},{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(max-width:900px)","sizes":"100vw","intrinsicwidth":"0","intrinsicheight":"0"}]}}],"title":"<p><span class=\"drop-cap\" drop-cap=\"true\">WHAT TO WATCH</span></p>","cta_label":"SEE THE LIST","left_image":true}}'''
data = json.loads(data)

all_src = ['path/to/file/53339c03d67e6ee5-lesson-3.jpg']
for src in all_src:
    breadcrumb_finder(data, src, [], results)
    print(results)

這將確保串列將一直迭代。結果：

[['imagepanel', 'image', 0, 'scaled_image', 'art_directions', 0, 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg'], ['imagepanel', 'image', 0, 'scaled_image', 'art_directions', 1, 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']]

編輯：我更新了全域變數，results以免與區域變數混淆

uj5u.com熱心網友回復：

import json
import pprint
def breadcrumb_finder(json_dict_or_list, value):
    if json_dict_or_list == value:
        return [json_dict_or_list]
    elif isinstance(json_dict_or_list, dict):
        for k, v in json_dict_or_list.items():
            child = breadcrumb_finder(v, value)
            if child:
                return [k]   child
    elif isinstance(json_dict_or_list, list):
        lst = json_dict_or_list
        for i in range(len(lst)):
            child = breadcrumb_finder(lst[i], value)
            if child:
                if child[0] != "src" or str(i) not in found_srcs:
                    found_srcs.append(str(i))
                    return [str(i)]   child

data = r'''{"imagepanel":{"image":[{"scaled_image":{"classes":"w-full","aspect_ratios":"frame sm:4:3 xmed:4:3","art_directions":[{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(min-width:900.1px)","sizes":"50vw","intrinsicwidth":"1411","intrinsicheight":"1000"},{"alt":"River waves","src":"path/to/file/53339c03d67e6ee5-lesson-3.jpg","type":"jpg","media":"(max-width:900px)","sizes":"100vw","intrinsicwidth":"0","intrinsicheight":"0"}]}}],"title":"<p><span class=\"drop-cap\" drop-cap=\"true\">WHAT TO WATCH</span></p>","cta_label":"SEE THE LIST","left_image":true}}'''
data = json.loads(data)

all_src = ['path/to/file/53339c03d67e6ee5-lesson-3.jpg', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']
found_srcs = []
for src in all_src:
    nested_path = breadcrumb_finder(data, src)
    print(nested_path)

通過存盤找到的 srcs，您可以跳過它們。我發現最簡單的方法是在添加 src 編號之前，您可以像在代碼中一樣完全檢查和跳過該迭代。

輸出：

['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '0', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']
['imagepanel', 'image', '0', 'scaled_image', 'art_directions', '1', 'src', 'path/to/file/53339c03d67e6ee5-lesson-3.jpg']

標籤：Python 字典 递归

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