使用python对markdown标题进行排序

效果

排序前：

排序后：

方法一：使用regex直接对文件进行处理，无需依赖库 （推荐）

原理

找出所有的二级标题即可

#%%
filename = r"mysql.md"
text = open(filename,encoding='utf8').read()
text_lines = open(filename,encoding='utf8').readlines()
#%%
import re
regex = r"^##\s+(.*?\n)"
matches = re.finditer(regex, text, re.MULTILINE)
header_lines = [(x.group(0),x.group(1)) for x in matches]
#%%
li = []
for line in text_lines:
    if header_lines and line == header_lines[0][0]:
       li.append([header_lines[0][1],header_lines[0][0]])
       del header_lines[0]
    else:
        li[-1][1] = f"{li[-1][1]}{line}"
li.sort(key=lambda x:-int(x[0][0]))
#%%
with open(r"result.md","w",encoding="utf8") as f:
    f.write("".join([x[1] for x in li]))
#%%

方法二：使用markdown解析库进行处理

原理

使用 mistune 实现 md -> html
使用 bs4 进行修改html（变相操作md）
使用 html2text 实现 html -> md

代码：

#%%
filename = r"XXXXXXXXXXXXXXXXXXXXXX\mysql.md"
text = open(filename,encoding='utf8').read()
#%%
import mistune
markdown = mistune.create_markdown(renderer='html')
html = markdown(text)
#%%
from bs4 import BeautifulSoup
soup = BeautifulSoup(html, "lxml")
first_h2_tag = soup.find("h2")
# 查找下一个同级别标签
next_tag = first_h2_tag.find_next_sibling()
# 查找所有在两个h2标签之间的标签
li = [[f"{first_h2_tag.text}",f"{first_h2_tag}{next_tag}"]]
while next_tag:
    if next_tag.name != 'h2':
        li[-1][1] = f"{li[-1][1]}{next_tag}"
    else:
        li.append([f"{next_tag.text}",f"{next_tag}"])
    next_tag = next_tag.find_next_sibling()

li.sort(key=lambda x: -int(x[0][0]))
result = "".join([x[1] for x in li])
import html2text
# 将HTML转换为Markdown
markdown = html2text.html2text(result)
with open("result.md", "w",encoding="utf8") as f:
    f.write(markdown)