Programming Python, 3rd Edition

The Hello World Selector

Let’s get back to writing some code again. It’s time for something a bit more useful than the examples we’ve seen so far (well, more entertaining, at least). This section presents a program that displays the basic syntax required by various programming languages to print the string “Hello World,” the classic language benchmark.

To keep it simple, this example assumes that the string is printed to the standard output stream in the selected language, not to a GUI or web page. It also gives just the output command itself, not the complete programs. The Python version happens to be a complete program, but we won’t hold that against its competitors here.

Structurally, the first cut of this example consists of a main page HTML file, along with a Python-coded CGI script that is invoked by a form in the main HTML page. Because no state or database data is stored between user clicks, this is still a fairly simple example. In fact, the main HTML page implemented by Example 16-17 is mostly just one big pull-down selection list within a form.

Example 16-17. PP3E\Internet\Web\languages.html

<html><title>Languages</title> <body> <h1>Hello World selector</h1> <P>This demo shows how to display a "hello world" message in various programming languages' syntax. To keep this simple, only the output command is shown (it takes more code to make a complete program in some of these languages), and only text-based solutions are given (no GUI or HTML construction logic is included). ...