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Learning Python Design Patterns - Second Edition

You're reading from   Learning Python Design Patterns - Second Edition

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Product type Paperback
Published in Feb 2016
Publisher
ISBN-13 9781785888038
Length 164 pages
Edition 2nd Edition
Languages
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Authors (2):
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Gennadiy Zlobin Gennadiy Zlobin
Author Profile Icon Gennadiy Zlobin
Gennadiy Zlobin
Chetan Giridhar Chetan Giridhar
Author Profile Icon Chetan Giridhar
Chetan Giridhar
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Toc

Table of Contents (13) Chapters Close

Preface 1. Introduction to Design Patterns 2. The Singleton Design Pattern FREE CHAPTER 3. The Factory Pattern – Building Factories to Create Objects 4. The Façade Pattern – Being Adaptive with Façade 5. The Proxy Pattern – Controlling Object Access 6. The Observer Pattern – Keeping Objects in the Know 7. The Command Pattern – Encapsulating Invocation 8. The Template Method Pattern – Encapsulating Algorithm 9. Model-View-Controller – Compound Patterns 10. The State Design Pattern 11. AntiPatterns Index

Module-level Singletons


All modules are Singletons by default because of Python's importing behavior. Python works in the following way:

  1. Checks whether a Python module has been imported.

  2. If imported, returns the object for the module. If not imported, imports and instantiates it.

  3. So when a module gets imported, it is initialized. However, when the same module is imported again, it's not initialized again, which relates to the Singleton behavior of having only one object and returning the same object.

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Learning Python Design Patterns - Second Edition - Second Edition
Published in: Feb 2016
Publisher:
ISBN-13: 9781785888038
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