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Python

In Greek mythology, Python is the name of a a huge serpent and sometimes a dragon. Python had been killed by the god Apollo at Delphi. Python was created out of the slime and mud left after the great flood. He was appointed by Gaia (Mother Earth) to guard the oracle of Delphi, known as Pytho.
The programming language Python has not been created out of slime and mud but out of the programming language ABC. It has been devised by a Dutch programmer, named Guido van Rossum, in Amsterdam.

Origins of Python

Guido van Rossum wrote the following about the origins of Python in a foreword for the book "Programming Python" by Mark Lutz in 1996:
"Over six years ago, in December 1989, I was looking for a "hobby" programming project that would keep me occupied during the week around Christmas. My office (a government-run research lab in Amsterdam) would be closed, but I had a home computer, and not much else on my hands. I decided to write an interpreter for the new scripting language I had been thinking about lately: a descendant of ABC that would appeal to Unix/C hackers. I chose Python as a working title for the project, being in a slightly irreverent mood (and a big fan of Monty Python's Flying Circus)."

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This topic in German / Deutsche Übersetzung: Memoisation und Dekorateure

Python 2.7

This tutorial deals with Python Version 2.7
This chapter from our course is available in a version for Python3: Memoization and Decorators

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This website contains a free and extensive online tutorial by Bernd Klein, using material from his classroom Python training courses.

If you are interested in an instructor-led classroom training course, you may have a look at the Python classes
by Bernd Klein at Bodenseo. © kabliczech - Fotolia.com

Quote of the Day:

"It's easy to make mistakes that only come out much later, after you've already implemented a lot of code. You'll realize Oh I should have used a different type of data structure. Start over from scratch" (Guido Van Rossum)

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If you have the choice working with Python 2 or Python 3, we recomend to switch to Python 3! You can read our Python Tutorial to see what the differences are.

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Memoization and Decorators

Definition of Memoization

The term "memoization" was introduced by Donald Michie in the year 1968. It's based on the Latin word memorandum, meaning "to be remembered". It's not a misspelling of the word memorization, though in a way it has something in common. Memoisation is a technique used in computing to speed up programs. This is accomplished by memorizing the calculation results of processed input such as the results of function calls. If the same input or a function call with the same parameters is used, the previously stored results can be used again and unnecessary calculation are avoided.

Memoization can be explicitly programmed by the programmer, but some programming languages like Python provide mechanisms to automatically memoize functions.

Function Decorators in Python

Please continue with our article on Memoization in our Python3 tutorial. All the examples are running in Python2.x as well!

Previous Chapter: Decorators
Next Chapter: Passing Arguments