Practical Python

What is Python?

Python is an interpreted high level programming language. It is often classified as a “scripting language” and is considered similar to languages such as Perl, Tcl, or Ruby. The syntax of Python is loosely inspired by elements of C programming.

Python was created by Guido van Rossum around 1990 who named it in honor of Monty Python.

Why was Python created?

In the words of Python’s creator:

My original motivation for creating Python was the perceived need for a higher level language in the Amoeba [Operating Systems] project. I realized that the development of system administration utilities in C was taking too long. Moreover, doing these things in the Bourne shell wouldn’t work for a variety of reasons. … So, there was a need for a language that would bridge the gap between C and the shell.

Guido van Rossum

If your work environment requires the use of an HTTP proxy server, you may need to set the HTTP_PROXY environment variable to make this part of the exercise work. For example:

>>> import os

>>> os.environ['HTTP_PROXY'] = 'http://yourproxy.server.com'

Interactive Mode

When you start Python, you get an interactive mode where you can experiment.

If you start typing statements, they will run immediately. There is no edit/compile/run/debug cycle.

This so-called read-eval-print-loop (or REPL) is very useful for debugging and exploration.

Python is dynamically typed. The perceived “type” of a variable might change as a program executes depending on the current value assigned to it.

Python is case sensitive. Upper and lower-case letters are considered different letters. These are all different variables:

name = 'Jake'

Name = 'Elwood'

NAME = 'Guido'