Python Dictionaries: Your Data's Filing Cabinet

Imagine you store a friend's contact details as a list: ['Maya', 17, 'London', 'maya@email.com']. Now someone asks, 'What is her email?' You have to remember that email is at index 3. That's fragile — add one item and the whole thing shifts. Here is the warm-up question to get you thinking:

A Python dictionary stores data as key-value pairs. Think of a real dictionary: you look up a word (the key) and find its meaning (the value). In Python the same idea lets you label every piece of data so you can find it instantly by name. **Creating a dictionary** You use curly braces `{}`. Each entry is written as `key: value`, and entries are separated by commas. ```python student = { 'name': 'Maya', 'age': 17, 'city': 'London' } ``` Keys are usually strings. Values can be any data type — a string, integer, list, or even another dictionary. **Accessing a value** Use square brackets with the key name, or use `.get()`: ```python print(student['name']) # prints: Maya print(student.get('age')) # prints: 17 ``` Using `.get()` is safer: if the key does not exist it returns `None` instead of crashing. **Adding and updating entries** Assign a value to a key. If the key already exists, the value is updated. If it is new, the entry is added. ```python student['email'] = 'maya@email.com' # adds a new key student['age'] = 18 # updates existing key ``` **Removing an entry** Use `del` or the `.pop()` method. `.pop()` also returns the removed value, which can be useful. ```python del student['city'] # removes 'city' entirely removed = student.pop('age') # removes 'age' and stores 17 in 'removed' ``` **Why not just use a list?** Lists use numbered positions (indices). Dictionaries use meaningful labels (keys). When your data has natural names — like the fields of a contact card or a game character's stats — a dictionary makes your code far easier to read and maintain.