Year 9 Python recap

• Computing
• Lower Secondary (Key Stage 3)

Year 9 Python Recap

Go to Lessonup.com.

Enter the on-screen code.

Constructs of Programming

x = 10

if x > 5:

    print("x is greater than 5")

else:

    print("x is not greater than 5")

for i in range(5):

    print(i)

Repetition of a process until something specific happens.

Run in a specified order.

Run in an order based on decisions or questions.

name = "Alice"

age = 30

print("Name:", name)

print("Age:", age)

fruits = ["apple", "banana", "cherry"]

for fruit in fruits:

    print(fruit)

x = 10

if x > 5:

    print("x is greater than 5")

elif x == 5:

    print("x is equal to 5")

else:

    print("x is less than 5")

Constructs of Programming 2

Selection

Iteration

Repetition of a process until something specific happens.

Run in a specified order.

Run in an order based on decisions or questions.

Sequencing

Key Objectives

All: Identify the three key programming constructs and loops.

 Most: Code the three key constructs and loops.

Some: Understand the purpose of the three key constructs and loops.

What are these an example of?
a = 0
name = "Mr. Motley"

1. Selection
2. User input
3. Declaring variables
4. Iteration

num1 = 10
num2 = 5
result = num1 - num2 * 2
What is the value of result?

1. 0
2. 5
3. -5
4. 20

Code task

Carlie's Carpets has hired you to develop a simple app to calculate how much carpet each customer needs.

Write a Python program that calculates the area of a rectangle given its length and width. 

Prompt the user to enter the length and width as inputs.

Calculate and display the area of the required carpet.

Open a new trinket here.  Comment breakdown here.

The ideal 5-minute answer

Compare with your trinket.

Did you use a float?

Why wouldn't you use an integer?

Think: Three loops?

Silent and solo: 

What are the three kinds of loop?

What is each one for?

Pair: Three loops?

In pairs:

Discuss what the three loops are.

Discuss what they're for.

One member of each pair:
Share the purpose of a "for loop".

For loops

A "for" loop is used to execute a block of code repeatedly until a specified condition is met. 

It's particularly useful when you know in advance how many times you want to execute a block of code.

# Iterate over elements in a list

numbers = [1, 2, 3, 4, 5]

for number in numbers:

    print(number)

One member of each pair:
Share the purpose of a "while loop".

While loops

A "while" loop is used in programming to execute a block of code repeatedly as long as a specified condition is true. 

The purpose of a while loop is to automate repetitive tasks and to iterate over a sequence of instructions until a certain condition is no longer met.

# Print numbers from 1 to 5 using a while loop

count = 1

while count <= 5:

    print(count)

    count += 1

Explain the purpose of a "do-while" loop.

Do-while loops

A "do-while" loop executes a block of code at least once and then repeats the execution based on a specified condition. 

The purpose of a do-while loop is to ensure that the block of code is executed at least once, regardless of whether the condition is initially true or false.

count = 0

while True:

    print(count)

    count += 1

    if count >= 5:

        break

Code task: Times Tables

Times Table Generator:

Task: 

Write a program that generates the times table for a number entered by the user three times. 

1. Use a for loop to iterate through the numbers from 1 to 10 and print the multiplication result for each.

2: Repeat this using a while loop.

3: Repeat this using a do-while loop.

Open a new trinket here.

Code task: Times Tables

Times Table Generator:

Task: 

Write a program that generates the times table for a number entered by the user three times. 

1. Use a for loop to iterate through the numbers from 1 to 10 and print the multiplication result for each.

2: Repeat this using a while loop.

3: Repeat this using a do-while loop.

Open a new trinket here.

How to do it with all three types of loop

Why would we use loops (iteration)?

Why loops?

Automation: Loops help automate repetitive tasks by executing the same code multiple times without manual work. 

Iterating over Data: Loops allow programmers to iterate over data such as lists, arrays, or dictionaries. 

Reducing Code Redundancy: Instead of writing the same code multiple times for each iteration, loops enable writing concise and efficient code by encapsulating the repetitive logic within a loop structure.

Scalability: Loops make programs scalable by allowing them to handle varying amounts of data or perform tasks a specific number of times.

Rate the Lesson

😒🙁😐🙂😃