1. CIT 590 Intro to Programming Object oriented programming

2. Agenda Finish up functional programming More on classes More discussion of style

3. Sieve example Functional programming lends itself to recursion really easily Erasthothenes algorithm for getting rid of composite numbers in a list of increasing numbers beginning with the number 2 An ancient algorithm for finding prime numbers From any list of increasing numbers remove the multiples of any number in the list Easy for list of size 1 Can I do this recursively???

4. The 3 argument version of the reduce function We have already seem reduce(function, list) There is a 3 argument variant which is Reduce(function, list, identity element/first element for the process Sorting examples Define insertion of an element into a sorted list Now use a reduce operation

5. Quicksort List comprehension = badass Quicksort.py - how to do something like quickSort in very few lines of code

6. More examples of classes Stacks Last in first out datastructure Python does not have stacks but you can use a list to simulate stacks See stacks.py in the repository

7. Object oriented design Think of your problem as a bunch of objects interacting with each other The way that an object interacts with another object is via the methods Library example A library is an object Within the library object I need to have books … make that another object These books get issued by patrons … make a patron object The library is the one that knows about all the patrons and all the books. An instance of a book does not need to care about patrons.

8. Inheritance revisited How to call a method of your parent class? What if the parent class does not want to define a method completely? We will explore this concept more fully when we do abstract classes in Java animals.py has examples of this

9. More examples of refactoring We’ll refactor refactoringExample.py Main goal = showing you how to declutter the main function