Reference library

Reliability & rate limiting

Retries, exponential backoff, circuit breakers, token buckets, and idempotent handlers.

4 matches

How to Implement a Rate Limiter in Python

A beginner-friendly Python class that tracks call timestamps with a deque to allow or block calls based on a max rate per time period.

rate-limit deque time

Python

import time
from collections import deque


class RateLimiter:
    """Simple rate limiter for beginners."""

    def __init__(self, max_calls: int, period_seconds: float):
        self.max_calls = max_calls
        self.period = period_seconds
        self.calls = deque()

    def allow(self) -> bool:
        """Retur…

16 0 Open

Reliability & rate limiting easy

How to Implement a Temporary Block in Python

Build a reusable PenaltyBox class that temporarily blocks access after a failure and reports remaining lockout time.

rate-limiting penalty-box lockout

Python

class PenaltyBox:
    def __init__(self, block_seconds: int = 30):
        self.block_seconds = block_seconds
        self._blocked_until = 0.0
        self._attempts = 0

    def try_access(self, current_time: float) -> bool:
        if self._blocked_until and current_time < self._blocked_until:
            return Fa…

14 0 Open

Reliability & rate limiting medium

How to implement a rate-limited shared counter in Python

Implements a thread-safe global counter that allows a maximum number of increments per second using a lock and time-based refill.

rate-limiting threading global-counter

Python

import threading
import time
import random

counter = 0
lock = threading.Lock()
MAX_CALLS_PER_SECOND = 3
last_refill = time.time()

def rate_limited_increment():
    global counter, last_refill
    with lock:
        now = time.time()
        if now - last_refill >= 1.0:
            last_refill = now
            count…

12 0 Open

Reliability & rate limiting easy

Rate Limit per User ID in Python with a Dict Mock

Implements a simple sliding window rate limiter using a defaultdict of timestamps per user ID, blocking requests that exceed a max count within a time window.

rate-limiting defaultdict sliding-window

Python

import time
from collections import defaultdict


class RateLimiter:
    def __init__(self, max_requests, window_seconds):
        self.max_requests = max_requests
        self.window_seconds = window_seconds
        self.user_timestamps = defaultdict(list)

    def allow_request(self, user_id):
        now = time.tim…

14 0 Open

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