February 2016
Beginner to intermediate
164 pages
3h 25m
English
book
Learning Python Design Patterns - Second Edition - Second Edition
by Chetan Giridhar, Gennadiy Zlobin
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Drawbacks of the Singleton pattern
While Singletons are used in multiple places to good effect, there can be a few gotchas with this pattern. As Singletons have a global point of access, the following issues can occur:
- Global variables can be changed by mistake at one place and, as the developer may think that they have remained unchanged, the variables get used elsewhere in the application.
- Multiple references may get created to the same object. As Singleton creates only one object, multiple references can get created at this point to the same object.
- All classes that are dependent on global variables get tightly coupled as a change to the global data by one class can inadvertently impact the other class.
Note
As part of this chapter, you learned ...
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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.
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.
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.
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.