Learning Python Application Development

Ninad Sathaye

• Éditeur: Packt Publishing
• Année: 2016
• ISBN:
  9781785889196
• Édition: 1
• Sujet: Informatica
• Sous-sujet: Sviluppo di applicazioni

Take Python beyond scripting to build robust, reusable, and efficient applications

About This Book

• Get to grips with Python techniques that address commonly encountered problems in general application development.
• Develop, package, and deploy efficient applications in a fun way.
• All-practical coverage of the major areas of application development, including best practices, exception handling, testing, refactoring, design patterns, performance, and GUI application development.

Who This Book Is For

Do you know the basics of Python and object oriented programming? Do you want to go an extra mile and learn techniques to make your Python application robust, extensible, and efficient? Then this book is for you.

What You Will Learn

• Build a robust application by handling exceptions.
• Modularize, package, and release the source distribution.
• Document the code and implement coding standards.
• Create automated tests to catch bugs in the early development stage.
• Identify and re-factor badly written code to improve application life.
• Detect recurring problems in the code and apply design patterns.
• Improve code efficiency by identifying performance bottlenecks and fixing them.
• Develop simple GUI applications using Python.

In Detail

Python is one of the most widely used dynamic programming languages, supported by a rich set of libraries and frameworks that enable rapid development. But fast paced development often comes with its own baggage that could bring down the quality, performance, and extensibility of an application. This book will show you ways to handle such problems and write better Python applications.

From the basics of simple command-line applications, develop your skills all the way to designing efficient and advanced Python apps. Guided by a light-hearted fantasy learning theme, overcome the real-world problems of complex Python development with practical solutions. Beginning with a focus on robustness, packaging, and releasing application code, you'll move on to focus on improving application lifetime by making code extensible, reusable, and readable. Get to grips with Python refactoring, design patterns and best practices. Techniques to identify the bottlenecks and improve performance are covered in a series of chapters devoted to performance, before closing with a look at developing Python GUIs.

Style and approach

The book uses a fantasy game theme as a medium to explain various topics. Specific aspects of application development are explained in different chapters. In each chapter the reader is presented with an interesting problem which is then tackled using hands-on examples with easy-to-follow instructions.

Learning Python Application Development

---

Table of Contents

Learning Python Application Development

Credits

Disclaimers

About the Author

About the Reviewer

www.PacktPub.com

eBooks, discount offers, and more

Why subscribe?

Preface

Important things to note

Very important note for e-book readers

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Developing Simple Applications

Important housekeeping notes

Installation prerequisites

Installing Python

Option 1 – official distribution

Option 2 – bundled distribution

Python install location

Unix-like operating systems

Windows OS

Verifying Python installation

Installing pip

Installing IPython

Choosing an IDE

The theme of the book

Meet the characters

Simple script – Attack of the Orcs v0.0.1

The game – Attack of the Orcs v0.0.1

Problem statement

Pseudo code – version 0.0.1

Reviewing the code

Running Attack of the Orcs v0.0.1

Using functions – Attack of the Orcs v0.0.5

Revisiting the previous version

Pseudo code with attack feature – Version 0.0.5

Reviewing the code

Running Attack of the Orcs v0.0.5

Using OOP – Attack of the Orcs v1.0.0

Prioritize the feature requests

Problem statement

Redesigning the code

Painting the big picture

Pseudo UML representation

Understanding the pseudo UML diagram

Reviewing the code

Running Attack of the Orcs v1.0.0

Abstract base classes in Python

Exercise

Summary

Very important note for e-book readers

2. Dealing with Exceptions

Revisiting Attack of the Orcs v1.0.0

Debugging the problem

Fixing the bugs…

Exceptions

What is an exception?

Most common exceptions

Exception handling

Raising and re-raising an exception

The else block of try…except

finally...clean it up!

Back to the game – Attack of the Orcs v1.1.0

Preparatory work

Adding the exception handling code

Running Attack of the Orcs v1.1.0

Defining custom exceptions

Preparatory work

Custom exception – The problem

Writing a new exception class

Expanding the exception class

Inheriting from the exception class

Exercise

Summary

3. Modularize, Package, Deploy!

Selecting a versioning convention

Serial increments

Using a date format

Semantic versioning scheme

Modularizing the code

Attack of the Orcs v2.0.0

Creating a package

Importing from the package

Releasing the package on PyPI

Prepare the distribution

Step 1 – Setting up the package directory

Step 2 – Writing the setup.py file

Step 3 – Updating the README and LICENSE.txt files

Step 4 – Updating the MANIFEST.in file

Step 5 – Build a deployment-ready distribution

Uploading the distribution

Step 1 – Creating an account on PyPI test website

Step 2 – Creating a .pypirc file

Step 3 – Register your project

Step 4 – Uploading the package

A single command to do it all

Installing your own distribution

Using a private PyPI repository

Step 1 – Installing pypiserver

Step 2 – Building a new source distribution

Step 3 – Starting a local server

Step 4 – Installing the private distribution

Making an incremental release

Packaging and uploading the new version

Upgrading the installed version

Version controlling the code

Git resources

Installing Git

Configuring your identity

Basic Git terminology

Creating and using a Git repository

Creating a bare remote repository

Clone the repository

Copying the code to the cloned repository

Staging the code and committing

Pushing the changes to the central repository

Using GUI clients for Git

Exercise

Summary

4. Documentation and Best Practices

Documenting the code

Docstrings

Introduction to reStructuredText

Section headings

Paragraphs

Text styles

Code snippets

Mathematical equations

Bullets and numbering

Dosctrings using RST

Docstring formatting styles

Automatically creating docstring stubs

Generating documentation with Sphinx

Step 1 – Installing Sphinx using pip

Step 2 – cd to the source directory

Step 3 – Running sphinx-quickstart

Step 4 – Updating conf.py

Step 5 – Running sphinx-apidoc

Step 6 – Building the documentation

Using sphinx-build

Using Makefile

Python coding standards

Code analysis – How well are we doing?

Code analysis using IDE

Pylint

Pylint in action

PEP8 and AutoPEP8

Exercise

Summary

5. Unit Testing and Refactoring

This is how the chapter is organized

Important housekeeping notes

Why test?

A new feature was requested

You implemented this feature

But something wasn't right...

It required thorough testing

Unit testing

Python unittest framework

Basic terminology

Creating tests with unittest.TestCase

Controlling test execution

Using unittest.TestSuite

Writing unit tests for the application

Set...