First useful OOP

I finally made a functional, useful class.



I've made functional classes before, but they were only for show. This is the first time I've used OOP that actually makes programming the rest of the application easier and more organized. I'm not saying I'm a believer in OOP for the sake of OOP, but it works for me here.

Creating a new instance of this class is easy - you have to pass it a legit .csv file (no checks yet, those are coming) and on creation it chucks the data in the .csv to a list, where each list element is a type dict with key/values that match the columns/values per row in the .csv. This alone took me for freaking ever to make work because it took me for freaking ever to get my head around these Python types.

Almost every method in the Cases class is about whittling down the internally stored list of cases. Calling CasesBySalesman(salesman) alters the internally stored list to just those by a particular salesman.

I labored heavily over how to do this in the most efficient way possible. The first incarnation of this class had each method return a new list, leaving the original untouched. This, I felt, left too much work to the program that would be using this class to handle. My knowledge of the "spirit" of OOP is limited since my experience is limited, but my favorite definition so far of a class is "data, and methods to perform actions on that data", so I went with that. There is a convenient reset method to go back to baseline if necessary.

So, in the eventual program that will use this class it would be as simple as:

A = Cases(file.csv)
A.CasesBySalesman("Bob")
A.OpenCases()

And A.caselist would be a list of dicts with the open cases for Bob. This seems very straightforward. My first pass mentioned above would have involved something like:

A = Cases(file.csv)
allcases = A.AllCases()
casesbybob = A.CasesBySalesman(allcases, "Bob")
casesbybobopen = A.OpenCases(casesbybobopen)

So yea, too many variables, and here I've reduced my Cases class to just a fancy holder of functions, instead of encapsulated methods to perform actions on internal data.

I think I made the right choice, and I'm quite happy with it.

EDIT: There is a copy/paste problem in the code above, but it's not important.