如何从嵌套字典文件的最深层提取文本？答案

【问题标题】：How to extract text from the deepest level of a nested dict file?如何从嵌套字典文件的最深层提取文本？
【发布时间】：2017-05-21 18:27:50
【问题描述】：

这个问题是What is the most efficient way to extract info from complex JSON files?的后续问题

我有大量的 dict 文件，其结构可以是任意的。当没有额外的嵌套时，我想捕获所有带有“text”键的字符串以及所有带有“htext”键的字符串。

d = {
        "section": {
                   "heading":{"lvl":"A1", "text":"today"},
                   "htext":[
                                {"color":"green",  "text":"yesterday", "htext":["a","b","c"]},
                                {"color":"purple", "text":"tomorrow"}
                               ]
                   }
         }

在上面的例子中，我希望我的结果是["today", "yesterday", "a", "b", "c", "tomorrow"]。

上一题提供的解决方案是：

def extract_text(obj, acc):
    if isinstance(obj, dict):
        for k, v in obj.items():
            if isinstance(v, (dict, list)):
                extract_text(v, acc)
            elif k == "text":
                acc.append(v)
    elif isinstance(obj, list):
        for item in obj:
            extract_text(item, acc)

我尝试通过将k == 'htext' 添加到elif 语句来修改此功能，但没有成功。我对 Python 有新的认识。非常感谢任何帮助！

【问题讨论】：

标签： python json dictionary recursion

【解决方案1】：

试试这个：

d = {
        "section": {
                   "heading":{"lvl":"A1", "text":"today"},
                   "htext":[
                                {"color":"green",  "text":"yesterday", "htext":["a","b","c"]},
                                {"color":"purple", "text":"tomorrow"}
                               ]
                   }
         }

acc = [];

def extract_text(obj, acc):
     if isinstance(obj, dict):
         for k, v in obj.items():
             if isinstance(v, dict):
                 extract_text(v, acc)
             elif k == "text":
                 acc.append(v)
             elif k == "htext" and isinstance(v, list) and all([isinstance(item, str) for item in v]):
                 for item in v:
                     acc.append(item)
             elif isinstance(v, list):
                 extract_text(v, acc)
     elif isinstance(obj, list):
         for item in obj:
             extract_text(item, acc)


extract_text(d, acc)
print(acc)

【讨论】：

【解决方案2】：

您可以检查键是否为“htext”，值是否为非嵌套列表：

def extract_text(obj, acc):
    if isinstance(obj, dict):
        for k, v in obj.items():
          if k == "htext" and isinstance(v, list) and not isinstance(v[0], (dict, list)):
             for x in v:
               acc.append(x) 
          elif isinstance(v, (dict, list)):
              extract_text(v, acc)
          elif k == "text":
              acc.append(v)

    elif isinstance(obj, list):
        for item in obj:
            extract_text(item, acc)

#=> ['yesterday', 'a', 'b', 'c', 'tomorrow', 'today']

【讨论】：