Plain-text Formatting In Python

I'm working on a program that makes new text files with python and I was wondering if it's possible to do some trivial text formatting when writing to a .txt file with python. For

Solution 1:

.txt files do not have formatting. You would have to use HTML or some other format of rich text/markup.

Example of HTML:

This is <b>bold</b> text. This is <u>underlined</u>.