Reference library

Dictionaries & sets

Key–value maps, uniqueness, counting, grouping, and fast lookups.

4 matches

Convert Lists and Dictionaries to Sets in Python

Convert lists of pairs into dictionaries and lists or dictionaries into sets using simple helper functions.

def convert_to_dict(data):
    """Convert list of tuples or lists into a dictionary."""
    return dict(data)


def convert_to_set(data):
    """Convert list or dictionary into a set of its keys/values."""
    if isinstance(data, dict):
        return set(data.keys())
    return set(data)


def convert_collection(data…

14 0 Open

Dictionaries & sets easy

How to Use Counter for Most Common Elements in Python

This code demonstrates how to find the most frequent elements in a list using Python's Counter class from the collections module.

collections counter frequency

Python

from collections import Counter

def most_common_elements(items, n=1):
    """Return the n most common elements and their counts."""
    counter = Counter(items)
    return counter.most_common(n)

if __name__ == "__main__":
    data = ["apple", "banana", "apple", "orange", "banana", "apple", "grape"]
    print(most_co…

13 0 Open

Dictionaries & sets easy

How to Use Dictionaries and Sets in Python for Beginners

Demonstrates Python dictionary operations and set operations with examples, including access, modification, defaults, and set algebra.

dictionary set beginner

Python

def demonstrate_collections():
    # Dictionary basics
    student = {
        "name": "Alice",
        "age": 20,
        "courses": ["Math", "Physics"]
    }
    print("Dictionary:", student)

    # Access and modify
    student["age"] = 21
    student["grade"] = "A"
    print("Modified:", student)

    # Get with d…

11 0 Open

Dictionaries & sets easy

How to Use Dictionaries and Sets in Python for Beginners

Introduces Python dictionaries and sets with practical examples including creating, modifying, and performing set operations, plus a word-frequency counter.

dictionaries sets data structures

Python

def demonstrate_dict_sets():
    # Create a dictionary with basic info
    person = {
        "name": "Alice",
        "age": 30,
        "city": "New York"
    }
    print("Dictionary:", person)

    # Access and modify dictionary values
    person["age"] = 31
    person["email"] = "alice@example.com"
    print("Afte…

15 0 Open

Browse by section

Each section groups closely related Python snippets.