python - 正则表达式 re.sub 关于文件字体问题

Question

这个问题在这里已经有了答案:





Is it possible to use PyYAML to read a text file written with a “YAML front matter” block inside?

(2 个回答)


去年关闭。




我试图从一个 .md 文件中检索前面的内容，当我的前面的每个标题都在一行中时，我可以检索内容。

前任:

---
title: "Meeting"
date: 2019-03-14T07:51:28+01:00
draft: false
status:["process", "todo"]
---

所以我写了下面的python脚本来获取前端内容

def get_front_matter(file, start='---', end='---'):
    """Strip file and retrieve front matter then format the value"""
    content = {}
    with open(file, 'r', encoding='UTF-8') as file_content:
        for content_line in file_content:
            if content_line.strip() == start:
                break
        for content_line in file_content:
            if content_line.strip() == end:
                break

            line_data = content_line.split(':', 1)
            # If we cannot split decently, carry on
            if len(line_data) != 2:
                continue
            # format the string to store in dict for better usage
            content[line_data[0]] = re.sub(r"[\n\t]*", "", line_data[1]).strip(' "')
    return content

但是如果我的前任 status 有多行，我就会面临一个问题。

---
title: "Meeting"
date: 2019-03-14T07:51:28+01:00
draft: false
status:
  [
    "process",
    "todo",
    "hold"
  ]
---

当我尝试阅读上述文件前言时，我得到 status 的空白值，但它应该如下所示:

{'title': 'Meeting', 'date': '2019-03-14T07:51:28+01:00', 'draft': 'false', 'teams': '["process", "todo", "hold"]'}

有没有其他方法可以根据行或标签读取前端内容的内容。我尝试了一些正则表达式，但无法检索一组行。

Answer 1

我把你的代码保存的差不多了，关键是在我们之前不要将值添加到结果中
确保我们收集了完整的 value (当它分成多行时) ，这是通过验证下一个 str 来完成的行，如果它是一个有效值 (key: some value)然后添加之前的 key与其 content结果或如果它是结束字符 --- ，我希望评论让事情更清楚

    def get_front_matter(file, start='---', end='---'):
        """Strip file and retrieve front matter then format the value"""
        result = {}
        with open(file, 'r', encoding='UTF-8') as file_content:
            for content_line in file_content:
                if content_line.strip() == start:
                    break

            content = ''
            key = ''
            for content_line in file_content:
                if content_line.strip() == end:
                    if key and content:
                        # add last key: content before breaking out
                        result[key] = re.sub(r"[\n\t]*", "", content).strip (' "')
                    break

                line_data = content_line.split(':', 1)
                if len(line_data) == 2 and not content:
                    # this is our first key: content, in this point we don't have previous content so we should keep them and check the next value first
                    key = line_data[0]
                    content = line_data[1]
                    continue
                elif len(line_data) == 2:  # we found another valid value 
                    # add previous (key, content) and keep the new (key , content)
                    result[key] = re.sub(r"[\n\t]*", "", content).strip(' "')
                    key = line_data[0]
                    content = line_data[1]
                else:
                    # not a valid key: value add it to previous value because it's a value splited in multiple line
                    content += content_line

        return result

备注 :我用结果更改了内容名称，对于这样的情况，此代码将中断:

     title: "Meeting"
    date: 2019-03-14T07:51:28+01:00
    draft: false
    status:
      [
        "somevalue:process",  # if the value contains ':'
        "todo",
        "hold"
      ]

在这里，您没有指定我们如何区分键和包含 ':' 的值，如果它前面没有它的键。我希望这不会使
你的问题