2 – Playlist

• Perform common operations on lists or individual items

• List
• index
• list item

• list operations (append, insert, pop, remove, index, count, reverse, sort, length)

• list membership
• Boolean/logical expression (condition)

• Perform operations on lists
• Brush up on your Python skills (mainly selection)

 Question

What do you think will be displayed on the screen when this program is executed?

Answer

The number 1 will be displayed.

This is the index of the value “Venus” in the list of planets.

There are many operations you can perform on lists and their items.

Python Code	Description
list.append(item)	add item at end of list
list.insert(index, item)	add item at index
list.pop(index)	remove item at index
list.remove(item)	remove item
list.index(item)	search for index of item
list.count(item)	get occurrences of item
list.reverse()	reverse list
list.sort()	sort list

Some Examples

• numbers.append(42)
• cities.insert(2, “Oslo”)
• last = values.pop()
• countries.remove(“Japan”)
• where = planets.index(“Mars”)
• nb_the = words.count(“the”)
• values.reverse()
• names.sort()

• You will be using pair programming, with each member in a pair taking on a specific role:
  • Driver: Controls the keyboard and mouse
  • Navigator: Provides support and instructions
• You will alternate between roles.

Complete the tasks on the worksheet you can download below to see how our view of the solar system has evolved over time.

To perform the tasks, you will need to perform operations on lists.

Task 1 – Planets

Task 2 – Dwarf Planets

• Here is how the Dice Battle game works with an example to help you.

• Roll – The attacker rolls three dice. The defender rolls two.
• Sort – Each player’s rolls are sorted in descending order (highest first).
• Check – Compare the players’ highest roll: lower loses a point.
• Compare the players’ second highest roll: lower loses a point.
• Ties are won by the defender.

Example Game

Roll – The attacker rolls three dice. The defender rolls two.

Sort – Each player’s rolls are sorted in descending order (highest first).

Check – Compare the players’ highest roll: lower loses a point.

Compare the players’ second highest roll: lower loses a point.

Ties are won by the defender.

The built-in len function returns the length (number of items) of a list.

Syntax:   len(list)

Examples

The in operator checks if a value is equal to any item in a list.

Expressions formed with in evaluate to either True or False.

Syntax:   item in list

Examples

Try out the len and in commands by searching through the book Dracula to find out how many words it has and how many times words like “vampire” appear. See if you can change which word you are searching for.

In this lesson, you…

• Performed operations on lists
• Brushed up on your Python skills (mainly selection)

In the next lesson, you will…

• Use iteration (while statements) to control the flow of program execution
• Practise using common operations on lists
• Perform operations on strings

• Upload the Activity 2 – The Solar System worksheet with Task 1 complete to the Silver badge task on Bourne to Learn.

• Upload the Activity 2 – The Solar System worksheet with Task 2 complete to the Gold badge task on Bourne to Learn.

• Upload the Activity 3 – Dice Battle worksheet to the Platinum badge task on Bourne to Learn.