two scoops of django 1.8 (PDF)

Two Scoops of Django
Best Practices For Django 1.8

Daniel Roy Greenfeld
Audrey Roy Greenfeld

Two Scoops of Django: Best Practices for Django 1.8
ird Edition, 2015-05-20

by Daniel Roy Greenfeld and Audrey Roy Greenfeld

c 2013-2015 Daniel Roy Greenfeld, Audrey Roy Greenfeld, and Two Scoops Press.
Copyright ⃝
All rights reserved. is book may not be reproduced in any form, in whole or in part, without written permission from the
authors, except in the case of brief quotations embodied in articles or reviews.
Limit of Liability and Disclaimer of Warranty: e authors have used their best efforts in preparing this book, and the
information provided herein “as is.” e information provided is sold without warranty, either express or implied. Neither the
authors nor Cartwheel Web will be held liable for any damages to be caused either directly or indirectly by the contents of
this book.
Trademarks: Rather than indicating every occurrence of a trademarked name as such, this book uses the names only in an
editorial fashion and to the bene t of the trademark owner with no intention of infringement of the trademark.
First Printing, April 2015
For more information, visit https://twoscoopspress.com.

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iv

Dedication

For Malcolm Tredinnick
1971-2013
We miss you.
http://2scoops.co/malcolm-tredinnick-memorial

v

About the Dedication
Malcolm Tredinnick wasn’t just a Django core developer and reviewer of “Two Scoops of Django:
Best Practices for Django 1.5.” To us, he was much, much more.
Daniel had worked with Malcolm Tredinnick in the summer of 2010, but we rst met him in person
at DjangoCon 2010. He was funny and charming, sharply opinionated but always a gentleman; we
instantly became close friends.
In 2012, when we co-organized the rst PyCon Philippines, as soon as we told him about it, Malcolm instantly declared he was coming. He gave two memorable talks and ran an impromptu all-day
Django tutorial. He also pushed and encouraged the local community to work on Filipino language
translations for Django, including Tagalog, Tausug, Cebuano, and more.
After the conference, we started working on a book about Django best practices. We gathered friends
and colleagues to help us as technical reviewers. Malcolm Tredinnick became the most active of them.
He was our mentor and forced us to dig deeper and work harder. He did this while working a day
job as the leader of a combined Rails and Haskell team; Malcolm was a true programming language
polyglot.
For our book, he provided so much assistance and guidance we tried to gure out a way to include
him in the author credits. When we told him about our dilemma, he laughed it off saying, “For a
book called ‘Two Scoops’, you can’t have three authors.” We suggested he share credit with us on
a second book, and he refused, saying he preferred to just comment on our work. He said that he
wanted people to have proper references, and for him, simply reviewing our work was contributing
to the greater good. Eventually the two of us quietly planned to somehow coerce him into being a
co-author on a future work.
After months of effort, we released the rst iteration on January 17th, 2013. Malcolm stepped back
from Two Scoops of Django, but we stayed in touch. Since Malcolm was unable to attend PyCon
US 2013 we weren’t sure when we would meet him again.
Two months later, on March 17th, 2013, Malcolm passed away.
We knew Malcolm for less than three years and yet he made an incredible difference in our lives.
We’ve heard many similar stories in the community about Malcolm; He was a friend and mentor to
countless others around the world. His last lesson to us went beyond code or writing, he taught us
to never take for granted friends, family, mentors, and teachers.

Contents
Dedication

v

About the Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Authors’ Notes

vi
xxvii

A Few Words From Daniel Roy Greenfeld . . . . . . . . . . . . . . . . . . . . . . . . . xxvii
A Few Words From Audrey Roy Greenfeld . . . . . . . . . . . . . . . . . . . . . . . . xxviii
Introduction

xxix

A Word About Our Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . xxix
Why Two Scoops of Django? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi
is book is intended for Django 1.8 and Python 2.7.x/3.3.3+ . . . . . . . . . . . . xxxi
Each Chapter Stands On Its Own . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi
Conventions Used in

is Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxii

Core Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiii
Keep It Simple, Stupid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiii
Fat Models, Utility Modules,

in Views, Stupid Templates . . . . . . . . . . . . xxxiv

Start With Django By Default . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiv
Be Familiar with Django’s Design Philosophies . . . . . . . . . . . . . . . . . . . xxxiv
e Twelve-Factor App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv
Our Writing Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv
Provide the Best Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv
Stand on the Shoulders of Giants . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxv
Listen to Our Readers and Reviewers . . . . . . . . . . . . . . . . . . . . . . . . xxxvi
Publish Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxvi
1

Coding Style

1

1.1

1

e Importance of Making Your Code Readable . . . . . . . . . . . . . . . . . .

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