[Tutor] Fwd: Re: Tips

[Alex Kleider]

On 2014-06-19 15:52, Steven D'Aprano wrote:
> On Thu, Jun 19, 2014 at 11:10:26AM -0700, Alex Kleider wrote:
> 
>> The idea of a singleton class is new to me as is this comparison of
>> class vs module.
>> Can anyone suggest a place to turn for more discussion of the topic?
>> thks, alexK
> 
> "Singleton" is one of the classic "design patterns", although these 
> days
> people are equally divided on whether it's a design pattern or
> anti-pattern.
> 
> The idea of design patterns is that they are a standard way of solving 
> a
> certain type of problem. For example, in the real world, there are
> various problems which have a certain factor in common:
> 
>     Example problems:
>     - Painting a mural on the ceiling. Building a house. Replacing
>       a broken window on the 2nd story. Making a tree house.
> 
>     Class of problem:
>     - There is work needed at a height well above what you can
>       reach from the ground.
> 
>     General solution:
>     - Use scaffolding to raise the height at which you can
>       comfortably work.
> 
> So "scaffolding" is the design pattern. Actual scaffolds may be made
> from many different materials (steel, timber, bamboo) and in many
> different shapes and sizes, but they're all scaffolds. Rather than 
> there
> being a "one size fits all" solution for all problems, instead there is
> a general solution that you customize for the specific problem. The 
> size
> and shape of the scaffolding needed to replace a broken window will be
> different than that needed to build a house.
> 
> Design patterns for software are like scaffolds: a design pattern is 
> not
> a language feature or function you can call, but a general technique to
> be used to solve a class of problems.
> 
> https://en.wikipedia.org/wiki/Design_pattern_%28computer_science%29
> 
> Explicit use of design patterns is very, very big in the Java and
> Dot Net worlds, less so in other programming languages.
> 
> 
> To learn more, Duck Duck Go is your friend:
> 
> https://duckduckgo.com/html/?q=singleton+design+pattern
> https://duckduckgo.com/html/?q=singleton+anti-pattern
> 
> If you still prefer Google:
> 
> https://www.google.com/search?q=singleton+design+pattern
> 
> or feel free to ask questions here.

You've got me thinking but I'm still at a loss as to what questions need 
asked!
The only applicability that fits in with anything I've experienced has 
to do with the necessity of globals to represent command line parameters 
which must be read at the outset and then be available to direct program 
execution.
Thanks for the "tip."
alex