OOP

Question 1

modularity

Answer 1

organizing principle: different components of sftwr sys divided into separate functional units (think module: collection of closely related classes/functions)

Question 2

abstraction

Answer 2

distill complicated system down to most fundamental parts

Question 3

ADT

Answer 3

mathematical model of data structure that specifies type of data stored, supported operations on them, types of parameters of operations

Question 4

duck typing

Answer 4

treats abstractions implicitly

Question 5

ABC

Answer 5

only purpose is to serve as base class through inheritance 
(how Python supports ADT's: defines 1 or more common methods that all implementations of abstraction must have)

Question 6

encapsulation

Answer 6

should not reveal internal details of implementations

Question 7

self

Answer 7

serves to identify particular instance upon which a member is invoked

Question 8

__init__ method

Answer 8

constructor of the class; establishes state of newly created object w/ appropriate instance variables

Question 9

operator overloading

Answer 9

implementing a specially named method
….ie, + operator overloaded by implementing __add__ method
a + b -> a.__add__(b)

Question 10

iterator

Answer 10

key behavior: supports special method __next__ : returns next element of collection, if any, or raises StopIteration exception

Question 11

generator

Answer 11

automatically produces iterator of yielded values

Question 12

Python provides automatic iterator implementation on classes that define:

Answer 12

__len__ & __getitem__

Question 13

lazy evaluation

Answer 13

represents the desired elements w/out storing explicitly in memory (rather than creating new instance); ie, range

Question 14

inheritance

Answer 14

allows new class (child class) to be defined based upon existing class (base/parent/super class)

Question 15

2 ways subclass differentiates from its superclass

Answer 15

• special existing behavior (overrides method)

- extend: provides new methods

Question 16

super().__init__

Answer 16

calls __ini__ method from parent class

Question 17

protected members

Answer 17

single underscore; accessible to subclasses, but not public

Question 18

private members

Answer 18

double underscore; not accessible to public or subclasses

Question 19

namespace

Answer 19

abstraction that manages all identifiers defined in particular scope (maps each name to its value)

Question 20

instance namespace

Answer 20

manages attributes specific to individual object (__init__)

Question 21

class namespace

Answer 21

manages members that are shared by all instances of class

Question 22

nested class

Answer 22

supports outer class (unrelated to inheritance)

Question 23

alias

Answer 23

ie, foo = bar: foo alias for bar

Question 24

shallow vs deep copy

Answer 24

shallow: can add/remove elements without affecting other, but if edit, changes both
deep: the new references its own copies of those objects referenced by original

Question 25

template method pattern

Answer 25

when an abc provides concrete behaviors that rely upon calls to other abstract behaviors (soon as subclass provides def's for missing abstract behaviors, inherited concrete behaviors well defined)

Question 26

metaclass

Answer 26

provides template for class def itself

Question 27

@abstractmethod

Answer 27

(declares methods to be abstract) don't provide implementation, but expect concrete subclasses to support those methods