Unit 1

Question 1

List the 5 Data Processing Functions

Answer 1

Sorting, Conversion, Analysis, Reporting, Aggregation

Question 2

List the 4 traits of good data

Answer 2

Reliable - Same data gives same results
Economical - Is not expensive to collect
Flexible - Can be used in all relevant circumstances
Relevant - Fit for purpose

Question 3

List the 4 parts of the event loop, in order

Answer 3

Event
Trigger
Event Handler
Event Loop

Question 4

How does quick sort work?

Answer 4

1 - Choose a pivot element.
2 - Iterate through each element.
3 - Each element less than the pivot element is placed in one sub-list, and all elements greater than the pivot element are placed in another.
4 - Repeat steps 2/3 on each sublist, until all the sublists have a length of one.
5 - Merge all the sublists.

Question 5

What are the pros and cons of quick sort?

Answer 5

Pros:

• Since the list is split, no more storage is needed.
• Fast with large lists

Cons:
- Worst case performance is similar to bubble/insertion

Question 6

How does insertion sort work?

Answer 6

Iterate through each element, compare to element before it. If smaller, compare to next etc until you find the right place to put it.

Question 7

What are the pros and cons of insertion sort?

Answer 7

Pros:

• Simple to write
• Sorts in-place so minimum memory requirements

Cons:
- Poor performance, performs badly with large datasets

Question 8

How does bubble sort work?

Answer 8

Iterate through each element, if the next element is smaller, swap them. Keep iterating through the dataset until no changes are made.

Question 9

What are the pros and cons of bubble sort?

Answer 9

Pros:

• Simple to write
• Easy to understand
• Sorted in place so little memory overhead

Cons:
- Not very efficient, time to process increases exponentially as data set size increases

Question 10

Properties of a tuple

Answer 10

• Ordered
• Indexable
• Immutable
• Static
• Duplicate elements are allowed

Question 11

Properties of a set

Answer 11

• Unordered
• Immutable
• Dynamic
• Non-indexed
• Duplicate elements are not allowed

Question 12

Properties of a dictionary

Answer 12

• Unordered
• Dynamic
• Mutable
• Duplicate keys not allowed
• Fast to search

Question 13

What are the primitive data types?

Answer 13

• Integer
• Float/Real
• String

Question 14

What is a record?

Answer 14

Stores related data. Implemented in Python as a dictionary inside of a dictionary.

Question 15

What is polymorphism?

Answer 15

When code has different forms for multiple different contexts (usually with different data types) and still works.

Question 16

What is encapsulation?

Answer 16

When a variable can only be accessed from within an object, and not from outside of it.

Question 17

What is overloading?

Answer 17

When multiple functions are defined with the same name but are called depending on argument types.

Question 18

What does OOP stand for?

Answer 18

Object Oriented Programming

Question 19

What is a class?

Answer 19

The blueprint for an object

Question 20

What is a method?

Answer 20

The associated actions of an object

Question 21

What is an instance?

Answer 21

An individual object created from a class

Question 22

What is an object?

Answer 22

A collection of data and its associated actions (methods)

Question 23

What is an attribute?

Answer 23

The individual properties of an object

Question 24

What is a subroutine?

Answer 24

A sequence of code that performs a specific task. This sequence of code can be called from wherever it is required.

Question 25

What is a procedure?

Answer 25

A subroutine that does not return a result

Question 26

What is a function?

Answer 26

A subroutine that returns a result

Question 27

What is the difference between a parameter and an argument?

Answer 27

Parameters the inputs of a subroutine. They are defined along with the subroutine (inside the brackets).

Arguments are the values that are given to the subroutine when it is called.

E.g.
def myFunc(parameter1, parameter2):
…

myFunc(argument1, argument2)

Question 28

Why should you generally avoid the use of global variables?

Answer 28

• They increase the complexity of the program
• They can cause conflicts with names written elsewhere
• They may be changed inadvertently