Python Data Structures Explained: Lists, Tuples, Sets, and Dictionaries

Python provides several built-in data structures to store and manipulate collections of data. In this guide, we'll explore the four most commonly used data structures: lists, tuples, sets, and dictionaries.

1. Lists

What is a List?

A list is an ordered, mutable collection of items. Lists can store elements of different data types.

Creating a List

fruits = ["apple", "banana", "cherry"]
numbers = [1, 2, 3, 4, 5]
mixed = [1, "apple", 3.14, True]

Common List Operations

Accessing Elements:
```
print(fruits[0])  # Output: apple
```
Slicing:
```
print(numbers[1:3])  # Output: [2, 3]
```
Adding Elements:
```
fruits.append("orange")
```
Removing Elements:
```
fruits.remove("banana")
```
Length of List:
```
print(len(fruits))  # Output: 3
```

2. Tuples

What is a Tuple?

A tuple is an ordered, immutable collection of items. Once created, its elements cannot be changed.

Creating a Tuple

coordinates = (10, 20)
colors = ("red", "green", "blue")

Common Tuple Operations

Accessing Elements:
```
print(coordinates[0])  # Output: 10
```

Slicing:

print(colors[1:3])  # Output: ("green", "blue")

Length of Tuple:
```
print(len(colors))  # Output: 3
```

3. Sets

What is a Set?

A set is an unordered collection of unique elements. Sets are useful for removing duplicates and performing mathematical operations like union and intersection.

Creating a Set

unique_numbers = {1, 2, 3, 4, 5}
vowels = {"a", "e", "i", "o", "u"}

Common Set Operations

Adding Elements:
```
unique_numbers.add(6)
```
Removing Elements:
```
unique_numbers.remove(3)
```

Set Operations:

set1 = {1, 2, 3}
set2 = {3, 4, 5}
print(set1.union(set2))  # Output: {1, 2, 3, 4, 5}
print(set1.intersection(set2))  # Output: {3}

4. Dictionaries

What is a Dictionary?

A dictionary is an unordered collection of key-value pairs. Keys must be unique and immutable (e.g., strings, numbers).

Creating a Dictionary

person = {"name": "Alice", "age": 25, "city": "New York"}

Common Dictionary Operations

Accessing Values:
```
print(person["name"])  # Output: Alice
```
Adding/Updating Elements:
```
person["email"] = "alice@example.com"
```
Removing Elements:
```
del person["age"]
```
Length of Dictionary:
```
print(len(person))  # Output: 3
```

When to Use Which Data Structure?

Lists: Use when you need an ordered, mutable collection of items.
Tuples: Use when you need an ordered, immutable collection of items.
Sets: Use when you need to store unique elements or perform set operations.
Dictionaries: Use when you need to store data as key-value pairs for quick lookups.

Next Steps

Now that you understand Python's core data structures, here are some next steps:

Practice using lists, tuples, sets, and dictionaries in small projects.
Explore advanced data structures like stacks, queues, and linked lists.
Learn how to combine these data structures for complex data manipulation.

Python's data structures are powerful tools for organizing and processing data. Happy coding!