Python Dictionaries Tutorial

📚 A dictionary in Python is a collection of key-value pairs that allows efficient data retrieval. Here's a quick guide to master this essential data structure!

What Are Dictionaries?

Dictionaries are unordered, mutable, and indexed collections. They store data in key-value pairs, where each key is unique and maps to a value.

🔍 Key Features:

• Fast lookups (average O(1) time complexity)
• Flexible keys (can be strings, numbers, or tuples)
• Dynamic resizing
• Nested structures (dictionaries can contain other dictionaries)

Basic Operations

Here are the most common operations you'll use with dictionaries:

1. Creating a Dictionary

   my_dict = {"name": "Alice", "age": 30}  
   

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2. Accessing Values

   print(my_dict["name"])  # Output: Alice  
   

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3. Updating Values

   my_dict["age"] = 31  
   

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4. Deleting Key-Value Pairs

   del my_dict["age"]  
   

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Practical Examples

Let's see dictionaries in action:

🛠️ Example 1:

student = {"id": 1, "score": 95, "subject": "Math"}  
print(student["score"])  # Output: 95  

🛠️ Example 2:

inventory = {"apples": 10, "bananas": 5, "oranges": 8}  
inventory["apples"] += 2  # Update stock  

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Common Use Cases

• Storing configuration settings
• Mapping user IDs to names
• Counting frequency of elements
• Implementing hash tables

🔗 For more advanced topics like dictionary methods or nested dictionaries, check out /en/Video_Tutorial/Python/Lists to explore related concepts!

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