Lesson 7: while Loops

Topics Covered:

• Understanding loops and repetition
• Using while loops to repeat code
• Controlling loops with conditions and break

What is a Loop?

Loops repeat code. A while loop runs as long as a condition is True:

count = 1

while count <= 5:
    print("Count is", count)
    count += 1

Infinite Loops

If the condition never becomes False, the loop will run forever. Use break to stop:

while True:
    command = input("Type 'exit' to quit: ")
    if command == "exit":
        break

Using a Condition to Control a Loop

Keep asking until the right answer is given:

password = ""

while password != "python":
    password = input("Enter the password: ")

print("Access granted!")

Activity: Count Down

Write a loop that counts down from 10 to 1:

num = 10

while num > 0:
    print(num)
    num -= 1

print("Blast off!")

Challenge Task

• Ask the user a math question like “What’s 2 + 2?”
• Repeat the question until they get it right

answer = 0

while answer != 4:
    answer = int(input("What is 2 + 2? "))

print("Correct!")