《think python》python书籍.pdf

Think Python
How to Think Like puter Scientist
Version
May 2013
Think Python
How to Think Like puter Scientist
Version
May 2013
Allen Downey
Green Tea Press
Needham, Massachusetts
Copyright © 2012 Allen Downey.
Green Tea Press
9 Washburn Ave
Needham MA 02492
Permission is granted to copy, distribute, and/or modify this document under the terms of the
mons Attribution-mercial Unported License, which is available at http:
///licenses/by-nc// .
The original form of this book is LATEX source code. Compiling this LATEX source has the effect of gen-
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The LATEX source for this book is available from
Preface
The strange history of this book
In January 1999 I was preparing to teach an introductory programming class in Java. I had
taught it three times and I was getting frustrated. The failure rate in the class was too high
and, even for students who eeded, the overall level of achievement was too low.
One of the problems I saw was the books. They were too big, with too much unnecessary
detail about Java, and not enough high-level guidance about how to program. And they all
suffered from the trap door effect: they would start out easy, proceed gradually, and then
somewhere around Chapter 5 the bottom would fall out. The students would get too much
new material, too fast, and I would spend the rest of the semester picking up the pieces.
Two weeks before the first day of classes, I decided to write my own book. My goals were:
• Keep it short. It is better for students to read 10 pages than not read 50 pages.
• Be careful with vocabulary. I tried to minimize the jargon and define each term at
first use.
• Build gradually. To avoid trap doors, I took the most difficult topics and split them
into a series of small steps.
• Focus on programming, not the programming language. I included the minimum
use