Dictionaries in Python

In Python, a dictionary is an important data structure, which is an unordered, mutable, and indexed collection. A dictionary is used to store data in the form of key-value pairs. Each key is unique and provides a reference to its value. Dictionaries are used when you need to find data quickly through a key.

Unordered, mutable, indexed by keys, and consists of key-value pairs where keys must be unique.

A dictionary can be created using curly braces `{}` or the `dict()` function.

You can access the value in a dictionary using its key. You can easily add new items or update existing ones by assigning a value to a key.

Standard Dictionary, Nested Dictionary, `defaultdict` (from the `collections` module), and `OrderedDict` (from the `collections` module).

You can remove items from a dictionary using the `del` statement or the `pop()` method.

Dictionaries have several built-in methods like `keys()`, `values()`, `items()`, and `get()`.