Python Data Structures

Core Data Structures

Lists

Ordered, mutable sequences. Best for collections that change.

# Creating lists
fruits = ["apple", "banana", "cherry"]

# Common operations
fruits.append("date")       # Add to end
fruits.insert(1, "blueberry")  # Insert at position
fruits.remove("banana")     # Remove by value

Dictionaries

Key-value pairs. Fast lookups by key.

# Creating dictionaries
person = {
    "name": "Ben",
    "role": "Data Engineer",
    "learning": True
}

# Common operations
person["skill"] = "Python"  # Add new key
value = person.get("name")  # Safe access

Sets

Unordered collections of unique items. Great for removing duplicates.

# Creating sets
unique_tags = {"python", "sql", "etl"}

# Common operations
unique_tags.add("docker")
unique_tags.remove("sql")

Tuples

Immutable sequences. Use for data that shouldn’t change.

# Creating tuples
coordinates = (10, 20)
config = ("localhost", 8080, True)

When to Use What

List: Need to modify the collection, order matters
Dict: Need fast lookups by key
Set: Need unique values, order doesn’t matter
Tuple: Data that shouldn’t change

Learning notes from Codecademy Python Fundamentals