Dictionaries in Python store keyvalue pairs from "summary" of Python For Dummies by Stef Maruch,Aahz Maruch
Dictionaries in Python are incredibly useful data structures because they allow you to store key-value pairs. This means that you can associate a specific value with a specific key, making it easy to retrieve the value later on. Think of a dictionary as a real-world dictionary - you look up a word (the key) to find its definition (the value). In Python, you can create a dictionary by enclosing key-value pairs in curly braces. For example, { "name": "John", "age": 30, "city": "New York" } is a dictionary with three key-value pairs. Each key in a dictionary must be unique, but the values can be repeated. This uniqueness of keys is what allows dictionaries to be so efficient - when you want to retrieve a value, you simply provide the key and Python can quickly look up the corresponding value. Dictionaries are mutable, meaning that you can change, add, or remove key-value pairs after the dictionary has been created. This flexibility makes dictionaries a powerful tool for managing data in Python programs. To access a value in a dictionary, you use the key within square brackets. For example, if you have a dictionary called person with the key "name", you can access the corresponding value by writing person["name"]. If the key does not exist in the dictionary, Python will raise a KeyError. You can also use the get() method to retrieve a value from a dictionary, which allows you to provide a default value if the key does not exist. Dictionaries are commonly used in Python for tasks such as storing configuration settings, mapping unique identifiers to data, and representing complex data structures. They are versatile and efficient, making them an essential tool for any Python programmer. By understanding how dictionaries store key-value pairs, you can take advantage of their flexibility and power in your own Python programs.
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