Challenge — Functions Decathlon

By the end of this lesson you can:

• Write a function from scratch given only its name, parameters and expected behaviour.
• Choose print vs return correctly for each event without being told which to use.
• Test your own functions in the main program by calling them and comparing the output to the expected output.

Set a timer for 50 minutes — the last 10 minutes are for the recap and the homework. Open one file, decathlon.py. Write all ten functions in it. Three rules to play by:

1. Read each brief carefully. The brief tells you the function's name, its parameters, what it should return (or print), and a worked example. Match the names exactly — the tests at the bottom call them by name.
2. No built-in shortcuts unless the brief says so. If an event says "write your own version of max", you don't use max. If it doesn't mention a built-in, use whatever you like.
3. Test as you go. Don't write all ten then run. Write event 1, scroll to the bottom, call it once with the example input, compare to the expected output, then move to event 2.

Event 1 · greet(name)

Prints Hello, <name>! on one line. No return needed.

greet("Aisyah")     # → Hello, Aisyah!
greet("Faiz")       # → Hello, Faiz!

Event 2 · square(n)

Returns n * n. No print inside.

print(square(6))    # → 36
print(square(11))   # → 121

Event 3 · is_odd(n)

Returns True if n is odd, else False. Use %.

print(is_odd(3))    # → True
print(is_odd(10))   # → False
print(is_odd(0))    # → False

Event 4 · add_three(a, b, c)

Returns the sum of three numbers. Three parameters.

print(add_three(1, 2, 3))      # → 6
print(add_three(10, 20, 30))   # → 60

Event 5 · max_of_two(a, b)

Returns the larger of two numbers. Use if/else — don't use the built-in max.

print(max_of_two(7, 4))    # → 7
print(max_of_two(2, 9))    # → 9
print(max_of_two(5, 5))    # → 5

Event 6 · is_vowel(letter)

Returns True if letter (a single character) is one of a, e, i, o, u — in any case. Else False. Hint: .lower() first.

print(is_vowel("a"))    # → True
print(is_vowel("E"))    # → True
print(is_vowel("z"))    # → False

Event 7 · countdown(n)

Prints n, then n-1, all the way down to 1, then prints Go!. Use a while loop (from PY-L1-12) or a for with range.

countdown(3)
# →
# 3
# 2
# 1
# Go!

Event 8 · total(nums)

Returns the sum of all numbers in the list. Don't use the built-in sum. Loop and accumulate.

print(total([1, 2, 3, 4]))      # → 10
print(total([10, 20, 30]))      # → 60
print(total([]))                # → 0

Event 9 · shout(text)

Returns text in upper case with !!! stuck on the end. Use .upper() (from PY-L1-23) and string +.

print(shout("hello"))         # → HELLO!!!
print(shout("ayam goreng"))   # → AYAM GORENG!!!

Event 10 · fizz_buzz_one(n)

The classic interview question, one number at a time. Return "FizzBuzz" if n is divisible by both 3 and 5; "Fizz" if just 3; "Buzz" if just 5; otherwise return str(n) — yes, cast the number to a string so all four return values are the same type.

print(fizz_buzz_one(3))     # → Fizz
print(fizz_buzz_one(5))     # → Buzz
print(fizz_buzz_one(15))    # → FizzBuzz
print(fizz_buzz_one(7))     # → 7      (as a string "7")
print(fizz_buzz_one(30))    # → FizzBuzz

Gotcha for event 10. Check the "both" case first. If you check n % 3 == 0 first, the 15 case will return "Fizz" instead of "FizzBuzz" and never reach the both-check.

Don't reinvent the file structure. Use this skeleton:

# decathlon.py — Functions Decathlon

# ---- Event 1 ----
def greet(name):
    # your code here
    pass    # placeholder so the file runs while empty

# ---- Event 2 ----
def square(n):
    pass

# ... events 3..10 ...

# ===== TESTS =====
print("Event 1:")
greet("Aisyah")
greet("Faiz")

print("Event 2:")
print(square(6))
print(square(11))

# ... add tests as you finish each event ...

The pass keyword is a polite Python placeholder — it lets a function body be empty without crashing the file. Replace it with real code as you finish each event.

Write your tests in the same order as your events, and add them as you go. When all ten tests print the right answers, you've won.

When you think you're done, ask yourself:

• Did every event that says returns actually use return, not print?
• Did every event that says prints actually use print, not return?
• For booleans (Events 3 and 6) — did you return True/False directly, not the strings "True"/"False"?
• For Event 10 — did you check the FizzBuzz case before the Fizz-only case?

Ten tiny functions, one file, sixty minutes. The decathlon was a deliberate sweep through everything PY-L1-26 to PY-L1-33 taught you — no parameters, one parameter, multiple parameters, defaults, boolean returns, list parameters, string methods, loops inside functions, returning vs printing. If you got all ten tests passing, you have everything you need for Hangman and the capstone. If a few got away from you, write down which ones and re-try them tonight — they'll all show up again. Tomorrow we start a three-part Hangman build.