Hands-On RESTful Python Web Services: Develop RESTful web services or APIs with modern Python 3.7, 2nd Edition

490 Pages·2018·11.803 MB·English

by  Gaston C. Hillar

Hands-On RESTful Python Web
Services
Second Edition
Develop RESTful web services or APIs with modern Python
3.7
Gaston C. Hillar
BIRMINGHAM - MUMBAI
Hands-On RESTful Python Web Services
Second Edition
Copyright © 2018 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form
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Packt Publishing has endeavored to provide trademark information about all of the companies and products
mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy
of this information.
Commissioning Editor: Aaron Lazar
Acquisition Editor: Reshma Raman
Content Development Editor: Rohit Singh
Technical Editor: Gaurav Gala
Copy Editor: Safis Editing
Project Coordinator: Vaidehi Sawant
Proofreader: Safis Editing
Indexer: Priyanka Dhadke
Graphics: Alishon Mendonsa
Production Coordinator: Shraddha Falebhai
First published: October 2016
Second edition: December 2018
Production reference: 1221218
Published by Packt Publishing Ltd.
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ISBN 978-1-78953-222-7
www.packtpub.com
To my sons, Kevin and Brandon, and my wife, Vanesa.
– Gaston C. Hillar
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Contributors
About the author
Gaston C. Hillar is Italian and has been working with computers since he was 8 years old.
Gaston has a Bachelor's degree in computer science (graduated with honors) and an MBA.
Currently, Gaston is an independent IT consultant and a freelance author who is always
looking for new adventures anywhere in the world.
He was a senior contributing editor at Dr. Dobb's, and has written more than a hundred
articles on software development topics. He has received the prestigious Intel® Black Belt
Software Developer award eight times. He has written many articles about Java for Oracle
Java Magazine.
Gaston was also a former Microsoft MVP in technical computing. He lives with his wife,
Vanesa, and his two sons, Kevin and Brandon.
While writing this book, I was fortunate enough to work with an excellent team at Packt
Publishing Ltd, whose contributions vastly improved its presentation. Reshma Raman
allowed me to provide her with ideas for developing the second edition of this book and I
jumped at the exciting prospect of teaching how to use many popular web frameworks for
developing RESTful web services with modern Python 3.6 and 3.7. Rohit Singh helped me
realize my vision for this new edition of the book and provided many sensible suggestions
regarding the text, the format, and the flow. I would like to thank my technical reviewers
and proofreaders for their thorough reviews and insightful comments. I was able to
incorporate some of the knowledge and wisdom they have gained during their many years
in the software development industry. This book was possible because they provided
valuable feedback.
I usually start writing notes about ideas for a book when I spend time at software
development conferences and events. I wrote the initial idea for the first edition of this book
in San Francisco, California, at Intel Developer Forum 2015. One year later, at Intel
Developer Forum 2016, I had the opportunity to discuss the book I was completing with a
number of software engineers and incorporate their suggestions in the final drafts of the
first edition. I started writing notes for the second edition in San Jose, California, at
Sensors Expo 2018.
The entire process of writing a book requires a huge number of lonely hours. I wouldn't be
able to write an entire book without dedicating some time to play soccer against my sons,
Kevin and Brandon, and my nephew, Nicolas. Of course, I never won a match. However, I
did score a few goals.
About the reviewers
Norbert Máté is a web developer who started his career back in 2008. His first
programming language as a professional web developer was PHP, before moving on to
JavaScript/Node.js and Python/Django/Django Rest Framework. He is passionate about
software architecture, design patterns, and clean code. Norbert has reviewed other Django
books, including Django RESTful Web Services.
Sanjeev Jaiswal is a Computer Graduate from CUSAT with 9 years of industrial
experience. He uses Perl, Python, AWS, and GNU/Linux for his day-to-day activities. He is
currently working on projects involving penetration testing, source code review, and
security design and implementations in AWS and cloud security projects. He is currently
learning about DevSecOps and security automation as well. Sanjeev loves teaching
engineering students and IT professionals. He has been teaching in his leisure time for the
last 8 years. He has written Instant PageSpeed Optimization and co-authored Learning Django
Web Development for Packt Publishing.
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Table of Contents
Preface 1
Chapter 1: Developing RESTful APIs and Microservices with Flask 1.0.2 9
Designing a RESTful API to interact with a simple data source 10
Understanding the tasks performed by each HTTP method 12
Understanding microservices 13
Working with lightweight virtual environments 14
Setting up a virtual environment with Flask and Flask-RESTful 20
Declaring status codes for the responses with an enumerable 21
Creating the model 24
Using a dictionary as a repository 25
Configuring output fields 26
Working with resourceful routing on top of Flask pluggable views 28
Configuring resource routing and endpoints 34
Making HTTP requests to the Flask API 35
Working with the curl and httpie command-line tools 37
Working with GUI tools – Postman and others 46
Consuming the API with other programming languages 55
Test your knowledge 55
Summary 57
Chapter 2: Working with Models, SQLAlchemy, and Hyperlinked APIs in
Flask 58
Designing a RESTful API to interact with a PostgreSQL 10.5
database 59
Understanding the tasks performed by each HTTP method 60
Installing packages with the requirements.txt file to simplify our
common tasks 62
Creating the database 64
Configuring the database 66
Creating models with their relationships 67
Creating schemas to validate, serialize, and deserialize models 70
Combining blueprints with resourceful routing 75
Understanding and configuring resourceful routing 85
Registering the blueprint and running migrations 86
Verifying the contents of the PostgreSQL database 90
Creating and retrieving related resources 92
Test your knowledge 100
Table of Contents
Summary 102
Chapter 3: Improving Our API and Adding Authentication to it with
Flask 103
Improving unique constraints in the models 104
Understanding the differences between the PUT and the PATCH
methods 111
Updating fields for a resource with the PATCH method 112
Coding a generic pagination class 114
Adding pagination features 119
Understanding the steps to add authentication and permissions 126
Adding a user model 128
Creating schemas to validate, serialize, and deserialize users 131
Adding authentication to resources 131
Creating resource classes to handle users 134
Running migrations to generate the user table 137
Composing requests with the necessary authentication 140
Test your knowledge 144
Summary 145
Chapter 4: Testing and Deploying an API in a Microservice with Flask 146
Setting up unit tests with pytest 146
Creating a database for testing 148
Creating fixtures to perform setup and teardown tasks for running
clean tests 151
Writing the first round of unit tests 152
Running unit tests with pytest and checking testing coverage 159
Improving testing coverage 164
Understanding strategies for deployments and scalability 171
Test your knowledge 174
Summary 175
Chapter 5: Developing RESTful APIs with Django 2.1 176
Designing a RESTful API to interact with a simple SQLite database 176
Understanding the tasks performed by each HTTP method 178
Setting up the virtual environment with Django REST framework 179
Creating the models 186
Managing serialization and deserialization 191
Understanding status codes for the responses 197
Writing API views 198
Making HTTP requests to the Django API 202
Working with command-line tools - curl and httpie 204
Working with GUI tools - Postman and others 213
Test your knowledge 217
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