Python Dictionaries in DSA
In this tutorial, we'll dive into Python Dictionaries, another essential data structure in Python. Dictionaries are versatile and widely used containers that allow us to store and manipulate collections of data in a unique way.
What is a Dictionary in Python?
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A dictionary in Python is an in-built data structure that serves as an unordered collection of key-value pairs.
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Just like lists use indexes to access elements, dictionaries use keys to access values.
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Each key is associated with a specific value, and these pairs are enclosed in curly braces {}.
Characteristics of Dictionaries
Here are the main characteristics of Python dictionaries:
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Unordered: Dictionaries are unordered, which means the elements do not have a specific sequence.
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Mutable: Dictionaries are mutable, allowing us to change, add, or remove key-value pairs after creation.
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Key-Value Pairs: Data is stored as key-value pairs, where each key maps to a unique value.
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Keys Are Unique: Keys in a dictionary must be unique. If we try to add a duplicate key, it will overwrite the existing value.
Creating Dictionaries
We can create a dictionary in Python using curly braces {} and specifying key-value pairs separated by colons (:). Here's an example:
my_dict = {"name": "Rohan", "age": 19, "city": "Indore"}
Common Dictionary Operations
Python dictionaries support various operations, including:
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Getting Keys: we can retrieve all keys from the dictionary using keys().
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Getting Values: we can retrieve all values from the dictionary using values().
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Getting Key-Value Pairs: we can retrieve all key-value pairs as tuples using items().
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Length: Find the number of key-value pairs in the dictionary.
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Clearing the Dictionary: we can remove all elements from the dictionary using clear().
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Copying a Dictionary: we can create a copy of a dictionary using dict().
You can check out practical examples of these operations in our Python Dictionary Tutorial.
