🐍 Lesson 7: Python Lists – Store Multiple Items in One Place

Welcome back! In this lesson, you’ll learn about lists — one of Python’s most commonly used data structures. Lists allow you to store multiple items in a single variable, making your programs more organized and efficient.

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⭐ What You Will Learn in This Lesson

• What lists are and how they work
• Accessing and modifying list items
• Adding and removing items
• Common list operations like loops and membership checks
• Using lists to organize multiple values efficiently

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👋 What Is a List?

A list is like a container that holds multiple items in a specific order. You can store numbers, strings, or even other lists inside a list.

fruits = ["apple", "banana", "cherry"]
print(fruits)

🧠 Output

['apple', 'banana', 'cherry']

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💾 Accessing Items in a List

Use indexes to access specific items. Python uses zero-based indexing.

print(fruits[0])  # apple
print(fruits[1])  # banana
print(fruits[-1]) # cherry (last item)

🧠 Output

apple
banana
cherry

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🛠 Modifying a List

You can change items using their index:

fruits[1] = "blueberry"
print(fruits)  # ['apple', 'blueberry', 'cherry']

🧠 Output

['apple', 'blueberry', 'cherry']

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➕ Adding Items to a List

• append() – adds to the end
• insert() – adds at a specific position

fruits.append("orange")
fruits.insert(1, "kiwi")
print(fruits)  # ['apple', 'kiwi', 'blueberry', 'cherry', 'orange']

🧠 Output

['apple', 'kiwi', 'blueberry', 'cherry', 'orange']

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➖ Removing Items from a List

• remove() – removes by value
• pop() – removes by index
• del – delete a specific index

fruits.remove("kiwi")
fruits.pop(1)
del fruits[0]
print(fruits)

🧠 Output

['blueberry', 'cherry', 'orange']

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⚡ List Operations

• Length: len(fruits)
• Check if item exists: "apple" in fruits
• Loop through a list:

for fruit in fruits:
    print(fruit)

🧠 Output

blueberry
cherry
orange

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👥 Who Is This Lesson For?

• Beginners learning to manage multiple items in Python
• Students wanting to store and organize data efficiently
• Developers looking to use lists in real programs

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❌ Common Mistakes

• Using the wrong index and getting an IndexError
• Trying to remove an item that doesn’t exist
• Mixing append() and insert() without understanding positions
• Modifying a list while looping through it incorrectly

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❓ Frequently Asked Questions (FAQ)

1. Can a list contain different types of items?

Yes! A list can hold strings, numbers, or even other lists.

2. How do negative indexes work?

Negative indexes start counting from the end of the list, e.g., -1 is the last item.

3. What happens if I access an index that doesn’t exist?

You’ll get an IndexError. Always check the list length first.

4. Can I loop through a list in reverse?

Yes, using slicing like fruits[::-1] or the reversed() function.

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🧪 Practice Exercises

1. Create a list of your five favorite movies.
2. Add one more movie to the list.
3. Remove a movie you don’t like.
4. Print each movie using a loop.
5. Check if a specific movie is in your list.

Bonus: Try sorting your list alphabetically using fruits.sort() and then printing it.

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🚀 What’s Next?

In the next lesson, you’ll learn about tuples, a similar data structure that is immutable. You’ll see how tuples differ from lists and when to use them.

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➡ Next Lesson

Go to Lesson 8 →