book

Python Programming with Design Patterns

Name: Python Programming with Design Patterns
Author: James W. Cooper
ISBN: 9780137579921

by James W. Cooper

December 2021

Intermediate to advanced

352 pages

10h

English

Addison-Wesley Professional

Read now

Unlock full access

Cover Page
About This eBook
Halftitle Page
Title Page
Copyright Page
Pearson’s Commitment to Diversity, Equity, and Inclusion
Dedication Page
Contents at a Glance
Table of Contents
Preface
Book Organization

Register Your Book
Acknowledgments
About the Author
Part I: Introduction
The tkinter LibraryGitHub
1. Introduction to Objects
The Class __init__ MethodVariables Inside a ClassCollections of ClassesInheritanceDerived Classes Created with Revised MethodsMultiple InheritanceDrawing a Rectangle and a SquareVisibility of VariablesTypes in PythonSummaryPrograms on GitHub
2. Visual Programming in Python
Importing Fewer NamesCreating an Object-Oriented VersionUsing Message BoxesUsing File DialogsUnderstanding Options for the Pack Layout ManagerUsing the ttk LibrariesResponding to User InputApplying Colors in tkinterCreating Radio ButtonsCommunicating Between ClassesUsing the Grid LayoutCreating CheckbuttonsAdding Menus to WindowsUsing the LabelFrameMoving OnExamples on GitHub
3. Visual Programming of Tables of Data
Creating a ListboxUsing a ComboboxThe Treeview WidgetMoving OnExample Code on GitHub
4. What Are Design Patterns?
Defining Design PatternsThe Learning ProcessNotes on Object-Oriented ApproachesPython Design PatternsReferences
Part II: Creational Patterns
5. The Factory Pattern
How a Factory WorksSample CodeThe Two SubclassesBuilding the Simple FactoryFactory Patterns in Math ComputationPrograms on GitHubThought Questions
6. The Factory Method Pattern
The Swimmer ClassThe Event ClassesStraight SeedingOur Seeding ProgramOther FactoriesWhen to Use a Factory MethodPrograms on GitHub
7. The Abstract Factory Pattern
A GardenMaker FactoryHow the User Interface WorksConsequences of the Abstract Factory PatternThought QuestionsCode on GitHub
8. The Singleton Pattern
Throwing the ExceptionCreating an Instance of the ClassStatic Classes As Singleton PatternsFinding the Singletons in a Large ProgramOther Consequences of the Singleton PatternSample Code on GitHub
9. The Builder Pattern
An Investment TrackerCalling the BuildersDisplaying the Selected SecuritiesConsequences of the Builder PatternThought QuestionsSample Code on GitHub
10. The Prototype Pattern
Cloning in PythonUsing the PrototypeConsequences of the Prototype PatternSample Code on GitHub
11. Summary of Creational Patterns
Part III: Structural Patterns
12. The Adapter Pattern
Moving Data Between ListsMaking an AdapterPrograms on GitHub
13. The Bridge Pattern
Creating the User InterfaceExtending the BridgeConsequences of the Bridge PatternPrograms on GitHub
14. The Composite Pattern
An Implementation of a CompositeSalary ComputationThe Employee ClassesBuilding the Employee TreePrinting the Employee TreeCreating a Treeview of the CompositeUsing Doubly Linked ListsConsequences of the Composite PatternA Simple CompositeOther Implementation IssuesPrograms on GitHub
15. The Decorator Pattern
Decorating a ButtonUsing a DecoratorUsing Nonvisual DecoratorsThe dataclass DecoratorUsing dataclass with Default ValuesDecorators, Adapters, and CompositesConsequences of the Decorator PatternPrograms on GitHub
16. The Façade Pattern
Building the Façade ClassesCreating Databases and TablesUsing the SQLite VersionConsequences of the FaçadePrograms on GitHubNotes on MySQLUsing SQLiteReferences
17. The Flyweight Pattern
What Are Flyweights?Example CodeCopy-on-Write ObjectsProgram on GitHub
18. The Proxy Pattern
Using the Pillow Image LibraryDisplaying an Image Using PILUsing Threads to Handle Image LoadingLogging from ThreadsCopy-on-WriteComparing Related PatternsPrograms on GitHub
19. Summary of Structural Patterns
Part IV: Behavioral Patterns
20. Chain of Responsibility Pattern
When to Use the ChainSample CodeThe ListboxesProgramming a Help SystemReceiving the Help CommandThe First CaseA Chain or a Tree?Kinds of RequestsConsequences of the Chain of ResponsibilityPrograms on GitHub
21. The Command Pattern
When to Use the Command PatternCommand ObjectsA Keyboard ExampleCalling the Command ObjectsBuilding Command ObjectsThe Command PatternConsequences of the Command PatternProviding the Undo FunctionSummaryReferencesPrograms on GitHub
22. The Interpreter Pattern
When to Use an InterpreterWhere the Pattern Can Be HelpfulA Simple Report ExampleInterpreting the LanguageHow Parsing WorksThe Console InterfaceThe User InterfaceConsequences of the Interpreter PatternPrograms on GitHub
23. The Iterator Pattern
Why We Use IteratorsIterators in PythonA Fibonacci IteratorFiltered IteratorsThe Iterator GeneratorA Fibonacci IteratorGenerators in ClassesConsequences of the Iterator PatternPrograms on GitHub
24. The Mediator Pattern
An Example SystemInteractions Between ControlsSample CodeMediators and Command ObjectsConsequences of the Mediator PatternSingle Interface MediatorsPrograms on GitHub
25. The Memento Pattern
When to Use a MementoSample CodeConsequences of the Memento PatternProgram on GitHub
26. The Observer Pattern
Example Program for Watching Colors ChangeThe Message to the MediaConsequences of the Observer PatternPrograms on GitHub
27. The State Pattern
Sample CodeSwitching Between StatesHow the Mediator Interacts with the StateManagerConsequences of the State PatternState TransitionsProgram on GitHub
28. The Strategy Pattern
Why We Use the Strategy PatternSample CodeThe ContextThe Program CommandsThe Line and Bar Graph StrategiesConsequences of the Strategy PatternPrograms on GitHub
29. The Template Pattern
Why We Use Template patternsKinds of Methods in a Template ClassSample CodeThe Triangle Drawing ProgramTemplates and CallbacksSummary and ConsequencesExample Code on GitHub
30. The Visitor Pattern
When to Use the Visitor PatternWorking with the Visitor PatternSample CodeVisiting Several ClassesBosses Are Employees, TooDouble DispatchingTraversing a Series of ClassesConsequences of the Visitor PatternExample Code on GitHub
Part V: A Brief Introduction to Python
31. Variables and Syntax in Python
Data TypesNumeric ConstantsStringsCharacter ConstantsVariablesComplex NumbersInteger DivisionMultiple Equal Signs for InitializationA Simple Python ProgramCompiling and Running This ProgramArithmetic OperatorsCombined Arithmetic and Assignment StatementsComparison OperatorsThe input StatementPEP 8 StandardsString MethodsExamples on GitHub
32. Making Decisions in Python
elif is “else if”Combining ConditionsThe Most Common MistakeLooping Statements in PythonUsing break and continuePython Line LengthThe print FunctionFormatting NumbersFormatting DatesUsing the Python match FunctionReferenceMoving OnSample Code on GitHub
33. Development Environments
IDLEThonnyPyCharmVisual StudioOther Development EnvironmentsCommand-Line ExecutionCPython, IPython, and Jython
34. Python Collections and Files
SlicingSlicing StringsChanging List ContentsCopying a ListReading FilesHandling ExceptionsUsing DictionariesUsing TuplesUsing SetsUsing the map FunctionWriting a Complete ProgramUsing List ComprehensionSample Programs on GitHub
35. Functions
Returning a TupleWhere Does the Program Start?SummaryPrograms on GitHub
Appendix A: Running Python Programs
If You Have Python InstalledCreating an Executable Python ProgramCommand-Line Arguments
Index
Code Snippets

Content preview from Python Programming with Design Patterns

28 The Strategy Pattern

The Strategy pattern is much like the State pattern in outline but is a little different in intent. The Strategy pattern consists of related algorithms encapsulated in a driver class called the Context. Either your client program can select one of these differing algorithms, or, in some cases, the Context might select the best one for you. As with the State pattern, the intent is to switch easily between algorithms without any monolithic conditional statements. The difference between the State and Strategy patterns is that the user generally chooses which of several strategies to apply, and only one strategy at a time is likely to be instantiated and active within the Context class. By contrast, as we have seen, it is ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.

Julian F.

Head of Cybersecurity

I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.

Addison B.

Field Engineer

I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.

Amir M.

Data Platform Tech Lead

I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.

Mark W.

Embedded Software Engineer

Publisher Resources

ISBN: 9780137579921

Cloud Computing

Data Engineering

Data Science

AI & ML

Programming Languages

Software Architecture

IT/Ops

Security

Design

Business

Soft Skills

Python Programming with Design Patterns

by James W. Cooper

28

The Strategy Pattern

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.