用Python-Markdown给md文件添加“内容表”（即table of contents)

So you finished writing a long article with Markdown and want a table of contents? Use Python-Markdown!
Just install it by:

pip install markdown 

And add [TOC] to your markdown file, like this:

# I like Python-Markdown
[TOC]
## What is Python-Markdown?
## Why do I like it?
### I just like it.
### Try it and you'll like it too.

Now run the following command:

python -m markdown -x toc input.md > output.html    

You can see for yourself the result in output.html