Day 11: List Operations — Lists That Change!

Lists Are Like Shopping Carts

When you shop on Amazon, you add items, remove items, and change quantities. Your cart grows and shrinks. A list works exactly the same way — it's not fixed, it can change anytime!

Add Items — append()

fruits = ["Apple", "Mango"]
fruits.append("Banana")
print(fruits)

Output: ['Apple', 'Mango', 'Banana']. append() adds to the end of the list. Just like adding a new item to your Swiggy order!

Remove Items — remove()

fruits = ["Apple", "Mango", "Banana"]
fruits.remove("Mango")
print(fruits)

Output: ['Apple', 'Banana']. Mango is gone! Just like removing an item from your cart before checkout.

Update Items

fruits = ["Apple", "Mango", "Banana"]
fruits[1] = "Grapes"
print(fruits)

Output: ['Apple', 'Grapes', 'Banana']. Position 1 was Mango, now it's Grapes. Like editing your delivery address on Zomato!

All Operations Together

cart = ["Burger", "Fries"]

cart.append("Coke")
cart.remove("Fries")
cart[0] = "Pizza"

print(cart)
print(len(cart))

Output: ['Pizza', 'Coke'] and 2. You just built a working shopping cart in 5 lines!

Common Mistakes

Mistake 1 — Forgetting quotes when appending text.

fruits.append(Banana)
fruits.append("Banana")

Mistake 2 — Using wrong index position.

fruits = ["Apple", "Mango", "Banana"]
print(fruits[3])
print(fruits[2])

Mini Challenge

Quick Quiz

Q: How do you add "Mango" to a list called fruits? A: fruits.append("Mango")

Q: How do you remove "Fries" from a list called cart? A: cart.remove("Fries")

Q: How do you change the first item in a list? A: listname[0] = "new value"

Key Takeaways