Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Modern Python Cookbook

You're reading from   Modern Python Cookbook The latest in modern Python recipes for the busy modern programmer

Arrow left icon
Product type Paperback
Published in Nov 2016
Publisher Packt
ISBN-13 9781786469250
Length 692 pages
Edition 1st Edition
Languages
Arrow right icon
Toc

Table of Contents (12) Chapters Close

Preface 1. Numbers, Strings, and Tuples 2. Statements and Syntax FREE CHAPTER 3. Function Definitions 4. Built-in Data Structures – list, set, dict 5. User Inputs and Outputs 6. Basics of Classes and Objects 7. More Advanced Class Design 8. Input/Output, Physical Format, and Logical Layout 9. Testing 10. Web Services 11. Application Integration

Reversing a copy of a list


Once in a while, we need to reverse the order of the items in a list collection. Some algorithms, for example, produce results in a reversed order. We'll look at the way numbers converted to a specific base are often generated from least-significant to most-significant digit. We generally want to display the values with the most-significant digit first. This leads to a need to reverse the sequence of digits in a list.

We have two ways to reverse a list. First, there's the reverse() method. Then there's this handy trick.

Getting ready

Let's say we're doing a conversion among number bases. We'll look at how a number is represented in a base, and how we can compute that representation from a number.

Any value, v, can be defined as a polynomial function of the various digits, dn, in a given base, b:

v = dn × bn + dn-1 × bn-1 + dn-2 × bn-2 + ... + d1 × b + d0

A rational number has a finite number of digits. An irrational number would have an infinite series of digits.

For...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at €18.99/month. Cancel anytime