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Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

8 matches
OOP & classes medium

How to Build a Linked List Node Class in Python

Create a Node class and a LinkedList class with insert, remove, and display methods to manage a singly linked list.

linked-list node oop
Python
class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

class LinkedList:
    def __init__(self):
        self.head = None

    def insert(self, data):
        new_node = Node(data)
        if not self.head:
            self.head = new_node
        else:
            current = self.…
12 0 Open
System design patterns medium

Implement a Consistent Hash Ring in Python

Build a minimal consistent hash ring with virtual nodes to map keys to servers stably as nodes are added or removed.

consistent-hashing hashing distributed-systems
Python
import hashlib
import bisect


class ConsistentHashRing:
    def __init__(self, nodes=None, replicas=3):
        self.replicas = replicas
        self.ring = {}
        self.sorted_keys = []
        if nodes:
            for node in nodes:
                self.add_node(node)

    def _hash(self, key):
        return i…
15 0 Open
Caching & Redis medium

Consistent Hashing Cache Shard in Python

A minimal consistent hashing ring with virtual nodes that distributes cache keys across shards and minimizes re-mapping when a node is removed.

caching sharding consistent-hashing
Python
import hashlib
import bisect


class ConsistentHashRing:
    def __init__(self, nodes=None, replicas=3):
        self.replicas = replicas
        self.ring = {}
        self.sorted_keys = []
        if nodes:
            for node in nodes:
                self.add_node(node)

    def _hash(self, key):
        return i…
16 0 Open
Big data & Spark medium

How to Build a DAG Execution Stage Calculator in Python

Computes the execution stages of a directed acyclic graph (DAG) by grouping nodes that become ready simultaneously using topological sorting with Kahn's algorithm.

dag topological-sort kahn-algorithm
Python
from collections import defaultdict, deque


def get_stages(edges):
    """Return list of stages, where each stage is a list of nodes
    that become ready at the same time in a DAG."""
    graph = defaultdict(list)
    in_degree = defaultdict(int)
    nodes = set()

    for src, dst in edges:
        graph[src].appen…
15 0 Open
ML engineering pipelines medium

How to Mock Kedro Pipeline Nodes in Python

Create a modular Kedro pipeline with node functions, namespacing, and input/output mapping to mock pipeline execution locally.

kedro pipeline modular
Python
from kedro.pipeline import Pipeline, node
from kedro.pipeline.modular_pipeline import pipeline as modular_pipeline


def preprocess(data: list) -> list:
    """Clean data by removing None values."""
    return [item for item in data if item is not None]


def transform(data: list) -> list:
    """Add 1 to each numeric…
15 0 Open
Database scaling & optimization medium

How to Implement Consistent Hashing in Python

Build a consistent hash ring in Python that distributes keys across nodes and minimizes remapping when nodes are added or removed.

consistent-hashing distributed-systems sharding
Python
import hashlib
from bisect import bisect_right


class ConsistentHashRing:
    def __init__(self, nodes, replicas=3):
        self.replicas = replicas
        self.ring = {}
        self.sorted_keys = []
        for node in nodes:
            self.add_node(node)

    def _hash(self, key):
        return int(hashlib.md…
15 0 Open
Database scaling & optimization medium

How to Simulate Colocated Shard Joins in Python

Groups shards by their node and merges co-located shards into a single logical unit, checking capacity constraints.

sharding database distributed-systems
Python
import random
from collections import defaultdict


def simulate_colocated_shards_join(nodes: list[dict], shards: list[dict]) -> dict:
    """
    Simulates the join of co-located shards (on the same node) into a single
    logical shard. Returns the resulting node-to-shard mapping.

    Each node: {'id': str, 'capaci…
11 0 Open
Database scaling & optimization medium

Snowflake ID Generator with Cluster Index Mock in Python

A thread-safe Snowflake ID generator mock that creates unique 64-bit IDs across simulated cluster nodes and maintains a sorted in-memory index for range queries.

snowflake id-generation clustering
Python
import time
import threading

class SnowflakeIDGenerator:
    def __init__(self, machine_id, datacenter_id):
        self.machine_id = machine_id
        self.datacenter_id = datacenter_id
        self.sequence = 0
        self.last_timestamp = -1
        self.machine_bits = 5
        self.datacenter_bits = 5
        …
13 0 Open

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