How to include code from a file

See https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-literalinclude.

1. Show line number: :linenos:. By default, line number counts from 0. To add an offset, e.g., 10, to the line number, use :lineno-start: 10. Note: It still includes all the contents of the file.

2. To emphasize a line, specified lines, or specified line ranges, use: :emphasize-lines: 10, :emphasize-lines: 10,12,14, and :emphasize-lines: 12,15-18 Note: emphasize means to change the background color.

3. Set the language, e.g., :language: python.

4. Set the caption, e.g., :caption: hello world.

5. To include a function from the python file, use :pyobject: my_func

6. To include specified lines, use :lines:1,3,5-10,15-. Note that if using this option, line number counts from 0. Use :lineno-start: xx to change the offset for display.