[Tutor] One shared object. class attribute or global variable?

[Alan Gauld]

> I've got a module that needs to share a pack of cards
>
> pack = ["14s", "2s", "3s", "4s", "5s", "6s", "7s", "8s", "9s", "10s", 
> "11s",
> ...
> random.shuffle(pack)
>
> do you think it is worth making a class with just this attribute
> or would this be a good place to use a global variable?

Classes with single attributes are almost never the right thing.
The question is what does the class *do*?
What are its responsibilities within the application?

You've already suggested that it could shuffle itself.
Maybe it could deal a random card too?
Maybe it could tell you something about how many cards are left?
Or whether a particular card is in the pack?

In that case creating a class makers sense. Classes without behaviour
are rarely useful. Data without fiunction is rare. Data and function is a 
class.

So if its only a bit of data themn sure make it a module level variable.
But ifd you are writing functions that operate on that data consider
makng it a class. Particul;arly if there could ever arise the need for
more than one pack - a game of Spider or Cribbage for example?

Alan G
Author of the learn to program web tutor
http://www.freenetpages.co.uk/hp/alan.gauld