In Python, a dictionary is an unordered collection of data values that consists of key-value pairs. Each key is unique and is associated with a specific value, allowing for efficient data retrieval and manipulation. This data structure is mutable, meaning that you can change its content after creation, which makes it suitable for various applications, such as processing data, managing configurations, and handling JSON or CSV files ²³.

Dictionaries can be created using curly braces {} or the dict() constructor. They are particularly useful for tasks that require fast lookups, as Python implements dictionaries as hashmaps, enabling quick access to values through their keys ³⁴. Additionally, dictionary comprehensions provide a concise way to create dictionaries, enhancing code readability ¹.

Understanding how to work with dictionaries is essential for developers, especially in data science and programming, as they are fundamental to many Python applications ³⁴.