Beginning Python - From Novice to Professional

CHAPTER 20
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Project 1: Instant Markup
In this project, you see how to use Python’s excellent text processing capabilities, including
the capability to use regular expressions to change a plain text file into one marked up in a
language such as HTML or XML. You need such skills if you want to use text written by people
who don’t know these languages in a system that requires the contents to be marked up.
Let’s start by implementing a simple prototype that does the basic processing, and then
extend that program to make the markup system more flexible.
ALPHABET SOUP
Don’t speak fluent XML? Don’t worry about that—if you have only a passing acquaintance with HTML, you’ll
do fine in this chapter. If you need an introduction to HTML, I suggest you take a look at Dave Raggett’s excellent
guide “Getting Started with HTML” at the World Wide Web Consortium’s Web site (http://www.w3.org/
MarkUp/Guide). For more information about XML, see Chapter 22.
What’s the Problem?
You want to add some formatting to a plain text file. Let’s say you’ve been handed the file from
someone who can’t be bothered with writing in HTML, and you need to use the document as a
Web page. Instead of adding all the necessary tags manually, you want your program to do it
automatically.
Your task is basically to classify various text elements, such as headlines and emphasized
text, and then clearly mark them. In the specific problem addressed here, you add HTML markup
to the text, so the resulting document can be displayed in a Web browser and used as a Web
page. However, once you have built your basic engine, there is no reason why you can’t add
other kind of markup (such as various forms of XML or perhaps ALTEX codes). After analyzing a
text file, you can even perform other tasks, such as extracting all the headlines to make a table
of contents.
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