book

Metaprogramming with Python

Name: Metaprogramming with Python
Author: Sulekha Aloorravi
ISBN: 9781838554651

by Sulekha Aloorravi

September 2022

Intermediate to advanced

402 pages

7h 28m

English

Packt Publishing

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Metaprogramming with Python
ContributorsAbout the authorAbout the reviewers
Preface
Who this book is forWhat this book coversTo get the most out of this bookDownload the example code filesDownload the color imagesConventions usedGet in touchShare Your Thoughts
Part 1: Fundamentals – Introduction to Object-Oriented Python and Metaprogramming
Chapter 1: The Need for and Applications of Metaprogramming
Technical requirementsAn overview of metaprogrammingMetaprogramming – a practical introductionMetadata of the add functionResolving type errors using metaprogrammingUnderstanding why we need metaprogrammingDon’t Repeat YourselfExploring the applications of metaprogrammingSummary
Chapter 2: Refresher of OOP Concepts in Python
Technical requirementsIntroducing our core exampleCreating classesUnderstanding objectsApplying methodsImplementing inheritanceExtending to multiple inheritanceUnderstanding polymorphismPolymorphism within inheritancePolymorphism in independent classesHiding details with abstractionProtecting information with encapsulationPrivate membersProtected membersSummary
Part 2: Deep Dive – Building Blocks of Metaprogramming I
Chapter 3: Understanding Decorators and their Applications
Technical requirementsLooking into simple function decoratorsUnderstanding function decorators with an applicationExchanging decorators from one function to anotherApplying multiple decorators to one functionExploring class decoratorsUnderstanding class decorators with an applicationGetting to know built-in decoratorsThe static methodThe class methodSummary
Chapter 4: Working with Metaclasses
Technical requirementsOverview of metaclassesThe structure of a metaclassAnalyzing the argumentsThe application of metaclassesInheriting the metaclassInheriting as a parent and metaclassSwitching metaclassesInheritance in metaclassesManipulating class variablesSummary
Chapter 5: Understanding Introspection
Technical requirementsIntroducing built-in functionsUsing the built-in id function Debugging unintentional assignments using idFinding out whether an object is callableChecking whether an object has an attributeChecking whether an object is an instanceChecking whether an object is a subclassUnderstanding the usage of propertyUsing property as a decoratorSummary
Chapter 6: Implementing Reflection on Python Objects
Technical requirementsIntroducing built-in functions used in reflectionUsing id to delete duplicatesUsing callable to dynamically check and generate methodsUsing hasattr to set valuesUsing isinstance to modify an objectUsing issubclass to modify a classApplying property on a classSummary

Chapter 7: Understanding Generics and Typing
Technical requirementsWhat are generics?How are generics connected to metaprogramming?How are generics handled in Python?What happens when data types are specified?Type hints as annotationsTyping with explicit type checks – approach 1Creating a class to implement type checking Creating a class to test type checkingTyping with explicit type checks – approach 2Creating a class to implement type checkingCreating a class to test type checking Adding data types with constraintsCreating a simple custom data typeCreating a domain-specific data typeSummary
Chapter 8: Defining Templates for Algorithms
Technical requirementsExplaining a sequence of operationsBack to our core exampleThe vegetables and dairy counterLess than 10 items counterThe greater than 10 items counterElectronics counterDefining the sequence of methodsThe vegetable counterLess than 10 items counterGreater than 10 items counterThe electronics counterIdentifying the common functionalitiesDesigning templatesSummary
Part 3: Deep Dive – Building Blocks of Metaprogramming II
Chapter 9: Understanding Code through Abstract Syntax Tree
Technical requirementsExploring the ast libraryInspecting Python code with abstract syntax treesReviewing simple code using astModifying simple code using astUnderstanding abstract syntax trees with applicationsUnderstanding the ast of a classModifying the ast of a code block by parsingModifying the ast of a code block by transforming nodesSummary
Chapter 10: Understanding Method Resolution Order of Inheritance
Technical requirementsUnderstanding the MRO of a classUnderstanding MRO in single inheritanceUnderstanding MRO in multiple inheritancesReviewing MRO in multilevel inheritanceUnderstanding the importance of modifying the order of inheritanceImpact of unintended change of order in inheritanceSummary
Chapter 11: Creating Dynamic Objects
Technical requirementsExploring type for dynamic objectsCreating multiple instances of a class dynamicallyCreating dynamic classesCreating multiple dynamic classesCreating dynamic attributes and methodsDefining attributes dynamicallyDefining methods dynamicallySummary
Chapter 12: Applying GOF Design Patterns – Part 1
Technical requirementsAn overview of design patternsExploring behavioral design patternsUnderstanding the chain of responsibilityLearning about the command design patternThe strategy design patternSummary
Chapter 13: Applying GOF Design Patterns – Part 2
Technical requirementsExploring structural design patternsUnderstanding the bridge patternUnderstanding the facade patternUnderstanding the proxy patternExploring creational design patternsUnderstanding the factory methodUnderstanding the prototype methodUnderstanding the singleton patternSummary
Chapter 14: Generating Code from AST
Technical requirementsGenerating a simple class with a templateGenerating multiple classes from a listGenerating a class with attributesGenerating a class with methodsGenerating a class with an init methodGenerating a class with a user-defined methodDefining a custom class factoryDeveloping a code generator to generate a simple librarySummary
Chapter 15: Implementing a Case Study
Technical requirementsExplaining the case studyDefining base classesDeveloping a code generator libraryGenerating code Designing an execution frameworkSummary
Chapter 16: Following Best Practices
Technical requirementsFollowing PEP 8 standardsIndentationNeat representationWriting clear comments for debugging and reusabilityAdding documentation stringsDocumentation string for metaprogrammingNaming conventions Class namesVariablesFunctions and methodsAvoiding the reuse of namesAvoiding metaprogramming where not requiredSummary
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Content preview from Metaprogramming with Python

Chapter 4: Working with Metaclasses

Metaclasses, the focal point of this chapter, can manipulate the way a new class is created by decorating the arguments without impacting the actual class definition itself. Metaclasses are not very frequently used in Python application development unless there is a need for more advanced implementations of frameworks or APIs that need features such as manipulation of classes or dynamic class generation and so on.

In the previous chapter, we looked at the concept of decorators with some examples. Understanding decorators helps in following metaclasses with more ease since both decorators and metaclasses deal with metaprogramming on Python 3 program objects by manipulating them externally.

In this chapter, ...

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Metaprogramming with Python

by Sulekha Aloorravi

Chapter 4: Working with Metaclasses

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