Preface

Software architecture, or creating a blueprint design for a particular software application, is not a walk in the park. The two biggest challenges in software architecture are keeping the architecture in sync, first with the requirements as they are uncovered or evolve, and next with the implementation as it gets built and evolves.

Filled with examples and use cases, this guide takes a direct approach to helping you with everything it takes to become a successful software architect. This book will help you understand the ins and outs of Python so that you can architect and design highly scalable, robust, clean, and performant applications in Python.

What this book covers

Chapter 1, Principles of Software Architecture, introduces the topic of software architecture, giving you a brief on architectural quality attributes and the general principles behind them. This will enable you to have strong fundamentals in software architectural principles and foundational attributes.

Chapter 2, Writing Modifiable and Readable Code, covers developmental architectural quality attributes, namely, modifiability and readability. It will help you gain an understanding of the architectural quality attribute of maintainability and tactics of writing code in Python to test your applications.

Chapter 3, Testability – Writing Testable Code, helps you understand the architectural quality attribute of testability and how to architect Python applications for testability. You will also learn about various aspects of testability and software testing and the different libraries and modules available in Python to write testable applications.

Chapter 4, Good Performance is Rewarding!, covers the performance aspects of writing Python code. You will be equipped with the knowledge of performance as a quality attribute in architecture and when to optimize for performance. You will learn when to optimize for performance in the SDLC.

Chapter 5, Writing Applications that Scale, talks about the importance of writing scalable applications. It discusses different ways to achieve of application scalability and discusses scalability techniques using Python. You will also learn about theoretical aspects of scalability and the best practices in the industry.

Chapter 6, Security – Writing Secure Code, discusses the security aspect of architecture and teaches you best practices and techniques of writing applications that are secure. You will understand the different security issues to watch out for and to and to architecture applications in Python that are secure from the ground up.

Chapter 7, Design Patterns in Python, gives you an overview of design patterns in Python from a pragmatic programmer's perspective, with brief theoretical background of each pattern. You will gain knowledge of design patterns in Python that are actually useful to pragmatic programmer.

Chapter 8, Python Architectural Patterns, introduces you to the modern architectural patterns in Python from a high-level perspective while giving examples of Python libraries and frameworks to realize the approaches of these patterns to solve high-level architecture problems.

Chapter 9, Deploying Python Applications, covers the aspect of easily deploying your code on remote environments or on the cloud using Python the right way.

Chapter 10, Techniques for Debugging, covers some of the debugging techniques for Python code—from the simplest, strategically placed print statement to logging and system call tracing which will be very handy to the programmer and also help the system architect to guide his team.

What you need for this book

To run most of the code samples shown in this book, you need to have Python 3 installed on your system. The other prerequisites are mentioned at the respective instances.

Who this book is for

This book is for experienced Python developers who are aspiring to become the architects of enterprise-grade applications or software architects who would like to leverage Python to create effective blueprints of applications.

Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "We can include other contexts through the use of the include directive."

A block of code is set as follows:

class PrototypeFactory(Borg):
    """ A Prototype factory/registry class """
    
    def __init__(self):
        """ Initializer """

        self._registry = {}

    def register(self, instance):
        """ Register a given instance """

        self._registry[instance.__class__] = instance

    def clone(self, klass):
        """ Return clone given class """

        instance = self._registry.get(klass)
        if instance == None:
            print('Error:',klass,'not registered')
        else:
            return instance.clone()

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

[default]
exten => s,1,Dial(Zap/1|30)
exten => s,2,Voicemail(u100)
exten => s,102,Voicemail(b100)
exten => i,1,Voicemail(s0)

Any command-line input or output is written as follows:

>>> import hash_stream
>>> hash_stream.hash_stream(open('hash_stream.py'))
'30fbc7890bc950a0be4eaa60e1fee9a1'

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Clicking the Next button moves you to the next screen."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

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