OOP: How to implement listing al 'Employees'.

[Petar]

On 28 dec, 19:42, Dennis Lee Bieber <wlfr... at ix.netcom.com> wrote:
> On Fri, 28 Dec 2007 04:05:59 -0800 (PST), Petar <peros... at gmail.com>
> declaimed the following in comp.lang.python:
>
> > I was just wondering.
>
> > What if you have a 'Employees' class and you want to list all the
> > employees. Currenlty i'm seeing to possibilities:
>
> > - create a 'listAll' function inside the class which returns all the
> > employees in a array.
> > - create multiple instances, putting them in a array, by calling the
> > Employees class multiple times in a loop (thus not creating a listAll
> > function in the class).
>
> > What is the better way of doing this? And should a class always
> > reference only on 'item'?
>
>         Bottom-up responses...
>
>         Unless you are contaminated by Java's need for a class to hold
> static functions, classes are just templates for an undefined object.
> You create an instance of the class to create a defined object. It is
> not common in Python to create a class that is not meant to be
> instantiated at least once (something that is just static methods is
> probably easier implemented as an import module with plain functions and
> module level globals).
>
>         Now, by "name", an "Employees" (plural s) class, to me, implies a
> class to represent a group of employees -- as a group! It would NOT have
> methods or members (both of which are just attributes in generic Python
> hissing) that refer to information about any specific employee -- such
> information should be part of an "Employee" (no S) class.
>
> aDept = Employees(dept="Finance")
> aDept.manager = Employee(name="John Dont", ID=3141596, phone="123-4567")
> aDept.addEmployee(Employee(name=....))
> aDept.addEmployee(Employee(...))
> ...
>         Note that this does not enforce any particular storage concept. The
> Employees (with the S) class could be using a list to store each
> employee, or a dictionary (maybe keyed by ID), or even an RDBM with a
> join (where one has tables for, say, department, employee, and
> intersection linking department to employee):
>
> select e.* from employees as e
> inner join dept_employee as de
> on de.empID = e.ID
> inner join departments as d
> on d.id = de.deptID
> where d.name = "Finance";
>
> aBody = aDept.employee(id=....)
>
> aDept.removeEmployee(id=...)
>
> aDept.printEmployees()
>
>         If all you need is a "list" of raw employees, with no meaning
> associated to the list... Then just use a list...
>
> aList = []
> aList.append(Employee(name=...))
> aList.append(Employee(...))
>
> for e in aList:
>         e.printEmployee()
> --
>         Wulfraed        Dennis Lee Bieber               KD6MOG
>         wlfr... at ix.netcom.com             wulfr... at bestiaria.com
>                 HTTP://wlfraed.home.netcom.com/
>         (Bestiaria Support Staff:               web-a... at bestiaria.com)
>                 HTTP://www.bestiaria.com/

I'm sorry if my question wasn't clear enough. But I think it has been
answered.

Let me explain how I got to this question. I had written een Article
class which handled the articles that I had. On a certain page I
wanted to show all the articles. That got me wondering about what to
do. Should I make a method in my Article.class which returned multiple
articles, or should I just use my current Article.class and fill a
list (with a loop) with articles. The first solution thus meaning
writing another method, the latter method to just use the current
Article.class and call it multiple times.

The post of Dennis made me realize of another solution though. To
create another class called Articles which return multiple articles.
The only problem I forsee with this that's it's gonna be a very empty
class.

Thank you all for your response, it has pointed me in the right
direction.