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Python Code Samples

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

3 matches
System design patterns medium

Inbox pattern consumer dedupe mock in Python

Implements a mock inbox consumer that deduplicates incoming messages by ID, with automatic eviction of old seen IDs to prevent unbounded memory growth.

deduplication inbox-pattern dataclasses
Python
import json
from collections import deque
from dataclasses import dataclass, field
from hashlib import sha256
from typing import Any


@dataclass
class InboxConsumer:
    max_seen: int = 1000
    seen_ids: set = field(default_factory=set)
    seen_history: deque = field(default_factory=deque)

    def _mark_seen(self,…
13 0 Open
Caching & Redis medium

How to Implement Probabilistic Early Expiration in Python

A Python mock of probabilistic early expiration for caches, using a heap-based expiry queue and random eviction to approximate cache stampede protection.

caching expiration heap
Python
import heapq
import random
import time


class ProbabilisticEarlyExpirationMock:
    def __init__(self, capacity=1024, expiration_probability=0.1):
        self.capacity = capacity
        self.expiration_probability = expiration_probability
        self._items = {}
        self._expiry_heap = []
        self._next_id…
14 0 Open
Caching & Redis medium

How to Implement an LFU Cache in Python

Implement a Least Frequently Used (LFU) cache with frequency tracking dictionaries to evict the least accessed items when capacity is reached.

lfu cache frequency
Python
class LFUCache:
    def __init__(self, capacity: int):
        self.capacity = capacity
        self.data = {}
        self.freq = {}
        self.min_freq = 0

    def get(self, key: int) -> int:
        if key not in self.data:
            return -1
        self._increment_freq(key)
        return self.data[key]

  …
12 0 Open

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