✨ Wizarding CodePython for muggles & wizards
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📦 Module 2

Lists

A single variable keeps overwriting itself. A list is your school trunk: many items, in order, ready to grab.

An inventor packs a magical trunk in neat rows while a tiny dragon adds a rubber duck.
Patch made a list of supplies. The list made a list of snacks. Nobody is sure who started it.

🪄 The concept

A list holds multiple values in order, using square brackets: ["wand", "cloak", "map"]. The first item is at index 0 (computers start counting at zero).

You can append() to add, pop() or remove() to take things out, insert() to place an item at a spot, and sort() to alphabetize.

Remember: = assigns a value; == checks if two values match. The word in asks whether something is inside a list — perfect for “do I know this spell?”

💬 Discussion

Talk these through with a friend, a class, or just your notes app:

  1. What lists already exist in your day? Playlists, class schedules, game inventories…
  2. Why does index 0 feel weird at first? Can you invent a memory trick?
  3. When would you rather use a list than twelve separate variables?

💻 Code walkthrough

Copy into your editor, or download the .py file and run it. Tinker — change names, numbers, and spells.

Creating and using lists inventory.py

# A list stores multiple items in order — like items in your trunk
inventory = ["wand", "cloak", "map"]
print(inventory[0])   # first item: wand (indexes start at 0)
print(len(inventory)) # how many items you are carrying

# append() adds to the end; pop() removes the last item (or one you choose)
inventory.append("time-turner")
found = inventory.pop()   # pick up the last item you added
print("You found:", found)
print("Still carrying:", inventory)

Assignment vs. equality list_basics.py

# = assigns a value; == checks whether two values match
favorite_spell = "Expelliarmus"   # assignment

if favorite_spell == "Expelliarmus":   # equality check
    print("Disarming charm ready!")
else:
    print("Different spell selected.")

# in checks whether something is inside a list
spells_known = ["Lumos", "Nox", "Accio"]
if "Accio" in spells_known:
    print("You know how to summon objects!")

List slicing (grab part of a list) list_slicing_grab_part_of_a_list.py

owls_subjects = ["Charms", "Potions", "Herbology", "Defense", "Astronomy"]

# [start:end] — end is not included; negative index counts from the end
first_two = owls_subjects[0:2]      # ["Charms", "Potions"]
last_one = owls_subjects[-1]        # "Astronomy"
middle = owls_subjects[1:4]         # three subjects in the middle

print("First exams:", first_two)
print("Final exam:", last_one)

insert, remove, and sort insert_remove_and_sort.py

team = ["Harry", "Ron", "Hermione"]

team.insert(1, "Neville")   # add at index 1 (second position)
team.remove("Ron")          # remove by value (must exist exactly once)
team.sort()                 # alphabetize the list in place

print("Quidditch squad:", team)
print("How many players:", len(team))

🧪 Try this

  1. Start with inventory.py. Add three of your own items, then print how many you are carrying with len().
  2. Build a list of five spells you wish you knew. Print only the first two using a slice, then print the last one with [-1].
  3. Make a Quidditch team list of friends (or characters). Insert a captain at index 0, remove one player, and sort the rest.

📁 Local files

All runnable Python for this module:

module-02-lists/ · all modules

🎬 Video lesson

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