Dictionaries in Python
Dictionaries are one of the most useful and flexible data structures in Python. They store data as key-value pairs – like a real dictionary where you look up a word (key) to find its definition (value).
Dictionaries are mutable, unordered (order is preserved from Python 3.7+), and keys must be unique and immutable (strings, numbers, tuples).
They’re perfect for representing real-world objects: a person with name/age, a product with price/stock, or settings with options.
Creating a Dictionary
Use curly braces {} with key: value pairs separated by commas.
Accessing Values
Use square brackets with the key, or .get() method (safer – returns None if key missing).
Adding and Updating Items
Just assign a value to a key – creates if missing, updates if exists.
Removing Items
Use del, pop(), or clear().
Looping Through Dictionaries
Loop over keys (default), values, or items.
Nested Dictionaries
Dictionaries can contain other dictionaries – great for complex data.
Quick Quiz
We have reviewed and checked the materials, but errors may still occur. The content is provided for educational purposes only, so use it at your own responsibility and verify with other sources if needed.
✨ Ask Lara — your AI study partner
Unlock personalized learning support. Lara can explain lessons, summarize topics, and answer your study questions — available from the Go plan and above.
Lara helps you learn faster — exclusive to ReadyTools Go, Plus, and Max members.
