Tutorial 7/15 REPEATING ACTIONS

Python: While Loops

Master the power of repeating logic until a condition is met.

The Hook

Ever seen a Loading Spinner?
It doesn't stop until the page is ready.

Computers excel at repeating tasks. A while loop keeps going as long as a condition stays True.

Building a simple Countdown generator.

n = 5

# Start at 5

while n > 0:

# Keep looping passes 0

print(n)

n = n - 1

# CRITICAL: Decrease n

print("Blastoff!")

# Runs after loop ends

Active Recall

We change the math. What exactly prints?

n = 1
while n < 10:
print(n)
n = n + 5

Level 16: Bronze

"The code counts down. Modify it to count UP to 10. Use n = 1 and n = n + 1."

n = 5
while n > 0:
    print(n)
    n = n - 1
print("Finished")

> bronze_stream_ready

Level 17: Silver

"This code runs forever! Add the missing line to decrease n so the loop eventually stops."

n = 5
while n > 0:
    print(n)
    # Missing something here!
print("Safe")

> debugger_idle

Level 18: Gold

Independent Construction Required

> security_module_standby