Reference library

Dictionaries & sets

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

3 matches

Build a Case-Insensitive Dict with a Wrapper Class in Python

Create a custom dict subclass that treats keys as case-insensitive by normalizing them to lowercase, with a full set of common dict methods.

dictionary case-insensitive wrapper

Python

class CaseInsensitiveDict:
    def __init__(self, data=None):
        self._data = {}
        if data:
            self.update(data)

    def __setitem__(self, key, value):
        self._data[str(key).lower()] = value

    def __getitem__(self, key):
        return self._data[str(key).lower()]

    def __delitem__(sel…

15 0 Open

Dictionaries & sets medium

How to Implement Disjoint Set Union Find in Python

Implement a Disjoint Set Union-Find data structure using a Python dictionary for parent tracking, with path compression and connectivity checks.

disjoint-set union-find graph

Python

class DisjointSet:
    def __init__(self):
        self.parent = {}

    def find(self, x):
        # Path compression
        if self.parent[x] != x:
            self.parent[x] = self.find(self.parent[x])
        return self.parent[x]

    def union(self, x, y):
        # Initialize if not present
        if x not in…

14 0 Open

Dictionaries & sets medium

Unflatten Dot Keys to Nested Dict in Python

Convert a flat dictionary with dot-separated keys into a nested dictionary structure using recursive setdefault loops.

dictionaries nested flatten

Python

def unflatten_dot_keys(flat_dict):
    result = {}
    for flat_key, value in flat_dict.items():
        parts = flat_key.split(".")
        current = result
        for part in parts[:-1]:
            current = current.setdefault(part, {})
        current[parts[-1]] = value
    return result


if __name__ == "__main_…

14 0 Open

Browse by section

Each section groups closely related Python snippets.