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Practice

Dictionary Methods and Nesting

Dictionaries in Python become especially powerful when you use built-in methods and nesting structures.

These techniques help you organize, update, and safely access complex data, which is a key skill in data analysis.


Why Use Dictionary Methods?​

Dictionary methods allow you to interact with data more efficiently:

  • .get() retrieves a value safely, even if the key does not exist.
  • .update() adds or modifies key-value pairs.
  • .pop() removes entries without needing to access them directly.

Using these methods can reduce errors and make your code easier to read.


What Is Nesting?​

Nesting means placing one data structure inside another, such as a dictionary inside another dictionary.

This is useful for representing complex or grouped information, for example storing multiple subjects and scores for each student.


Nested Dictionary Example​

Below is an example of a nested dictionary:

Nested Dictionary
# Create a nested dictionary for a student
student = {
    "name": "Alina",
    "grades": {
        "math": 88,
        "history": 92
    }
}

# Safely access a nested value
math_score = student["grades"].get("math", 0)
print("Math Score:", math_score)  # Output: 88

The student dictionary contains another dictionary inside the grades key.

The .get("math", 0) method looks for the "math" score.

  • If it exists, it returns the score (88).
  • If it does not, it returns the default value 0 instead of causing an error.

This approach is especially helpful when you work with real-world data that may be incomplete.

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