Caching & Redis
Cache-aside, TTL, invalidation, hot keys, and in-memory lookup patterns at scale.
Implement a TTL cache with a mock clock in Python
This code creates a simple TTL cache that stores values with an expiration timestamp and allows injecting a mock time function to test expiry behavior deterministically.
import time
from functools import wraps
class TTLCache:
def __init__(self, ttl_seconds):
self.ttl = ttl_seconds
self.cache = {}
self._now = time.time
def set_mock_time(self, mock_time_fn):
"""Inject a mock time function for testing TTL expiry."""
self._now = mock_time_…Redis-inspired sliding window rate limiter in Python
A pure-Python sliding window rate limiter using a deque of timestamps, mock-ready for Redis-backed production limits.
import time
from collections import deque
class SlidingWindowRateLimiter:
def __init__(self, max_requests: int, window_seconds: int) -> None:
self.max_requests = max_requests
self.window_seconds = window_seconds
self.requests: dict[str, deque] = {}
def is_allowed(self, client_id: str…Browse by section
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Caching & Redis — Python code examples
What you will find here
This page collects caching & redis snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.
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