1. Starter
You have been asked to write a program to store the names of everybody in a class. Assuming there are 20 pupils in the class, how would you do this?

2. Lists & Arrays
Python

3. Objectives
2.3.2 Understand the need for and be able to select and use data structures
one-dimensional arrays
two-dimensional arrays

4. What are Arrays?
If we think of variables as a box. Arrays are a collection of boxes.
Array - list of homogeneous items
Each “box” has an address starting at 0.
We call the address it’s INDEX
[0]
‘Alf’
[1]
‘Betsy’
[2]
‘Charlie’
[3]
‘David’

5. Printing Lists
Individual elements may be printed by using the name of the list and then the index of the element you wish to print in square [] brackets.
Think: What programming construct could you use to print out every element in a list?

6. Activity 1.
Complete Activity 1 the VLE.

7. More than one dimension?
We were working with 1 Dimensional Arrays.
These are effectively lists.
What about if we had lists….of lists???
[0]
[1]
[2]
[3]
[4]
What Value is at Scores[1][2]?
Jimmy 12 15 17 19
Joanna 9 16 18 20
Jess 5 6 7
John 4
[0] 16
[1]
[2]
[3]

8. Activity 1.
Complete Activity 2 the VLE.

9. To store related information
Week 2 - Recap
What is the purpose of a list?
How do you create a list?
Add an element?
Remove a element?
To store related information
scores = [35, 62, 98, 54, 21]
scores.append(71)
scores.pop(2)
Teacher note: Random numbers

10. Plenary If variables are like boxes, what are lists?
What methods can we use to add and remove elements to/from a list?
What is a list element?