How to Add TTL Jitter to Cache Expiration in Python

import random
import time
from functools import wraps

def add_jitter(ttl: float, jitter_range: float = 0.1) -> float:
    """Add random jitter (as % of TTL) to stagger cache expiration and prevent avalanche."""
    jitter = random.uniform(-jitter_range, jitter_range)
    return ttl * (1 + jitter)

def cache_with_jitter(ttl: float, jitter_range: float = 0.1):
    """Simple mock cache decorator with staggered TTL."""
    cache = {}

    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            key = (args, tuple(kwargs.items()))
            now = time.time()

            if key in cache:
                value, expiry = cache[key]
                if now < expiry:
                    return value
                else:
                    del cache[key]

            value = func(*args, **kwargs)
            effective_ttl = add_jitter(ttl, jitter_range)
            cache[key] = (value, now + effective_ttl)
            return value

        return wrapper
    return decorator

@cache_with_jitter(ttl=10, jitter_range=0.2)
def get_user_data(user_id: int) -> dict:
    return {"user_id": user_id, "name": f"User{user_id}"}

if __name__ == "__main__":
    # Simulate cache behavior for multiple items
    for _ in range(5):
        print(get_user_data(1))
    print("Cache hits with staggered TTL values (10s ± 20%)")