meet it

Big programs are small pieces working as a team.

Real programs are built from small parts. A list holds the data. A loop walks through it. A function answers one small question, and an if decides what to do with each answer.

Here, return rating >= 7 hands back True or False, so the answer slots straight into an if. Each piece is tiny, but together they spot every rating worth a yum.

When something goes wrong, you : find the bug, fix it, run again. Every programmer does this every day. Small functions help, because you can test each one on its own.

def is_tasty(rating):
    return rating >= 7
ratings = [9, 3, 8, 5]
for rating in ratings:
    if is_tasty(rating):
        print(f"{rating} out of 10. Yum!")

Test each function on its own first, then put the pieces together.

guess first

Every piece at once. What will this show?

Guess before you run it. Wrong guesses are how you learn, and nothing is marked.

def double(number):
    return number * 2
total = 0
for goal in [1, 2, 3]:
    total = total + double(goal)
print(total)

your turn

Your turn. Plan a trip to the snack shop.

Put three snack prices in the list, then type how much money you have in the last blank. Make sure you can afford at least one snack!

Your code

press run to see what happens

fix it

Only one Paris counts as right. Debug it!

Broken code to fix

press run to see what happens

Only one guess counts as right. What is different about the other two?
Python is case-sensitive, so Paris and paris are different strings. Change the guess before comparing.
On line 2, change guess to guess.lower(), then run.

nailed it

you put all the pieces together. :D

Small functions, each with one job, build big programs.
Lists hold data, loops walk through it, and if decides.
To debug, find the bug, fix it, then run again.

new words in your collection

debug

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