Convert MathJax in Obsedian to MathJax in Hugo

Hongtao Hao / 2022-05-11


In Obsedian, you just use:

But in Hugo, you need to use:

Similary,

$$Something here$$

needs to become

`$$Something here$$`

Then Obsedian and Hugo are the same.

Mathjax #

So, how to convert MathJax in Obsedian to that in Hugo?

We can use Python.

import re 

# reaf file
f = open('yourfile.md', 'r')
txt = f.read()

# this line is from 4castle: https://stackoverflow.com/a/38645273
txt = re.sub(r'\$([^$]*)\$', r'`$\1$`', txt)

txt = re.sub(r'`\$\$`([^$]*)`\$\$`', r'`$$\1$$`', txt)
with open('txt.md', 'w') as f:
    f.write(txt)

I’ll explain line by line.

re.sub(r'\$([^$]*)\$', r'`$\1$`', txt)

What this line does is to replace the pair of dollar sign with $$. Try that on txt = "$I want to do that$" and you’ll know that.

The problem is that the above pattern does not work for string like this:

$$I want to do that$$

will become

`$$`I want to do that`$$`

To solve the problem, we apply:

re.sub(r'`\$\$`([^$]*)`\$\$`', r'`$$\1$$`', txt)

Images #

Obsidian uses a different image importing method. Its format is like this:

![[hori-verti.png]]

But we want it to be like this in Markdown:

![](images/hori-verti.png)

This is a trivial task:

txt = "![[hori-verti.png]]"

# replace ![[ with ![](/image/
txt = re.sub(r'!\[\[', '![](/image/', txt)
# replace ]] with )
txt = re.sub(r'\]\]', ')', txt)

Script #

This is the script:

import re 

# the input obsedian file name
input_fname = 'calc.md'

# output file name
output_fname = 'txt.md'

# image directory
image_dir = '/media/enblog/calc-pics/'

# reaf file
f = open(input_fname, 'r')
txt = f.read()

# this line is from 4castle: https://stackoverflow.com/a/38645273
txt = re.sub(r'\$([^$]*)\$', r'`$\1$`', txt)

txt = re.sub(r'`\$\$`([^$]*)`\$\$`', r'`$$\1$$`', txt)

# replace ![[ with ![](/image/
txt = re.sub(r'!\[\[', f'![]({image_dir}', txt)
# replace ]] with )
txt = re.sub(r'\]\]', ')', txt)

with open(output_fname, 'w') as f:
    f.write(txt)

Last modified on 2022-10-01