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Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

6 matches
Concurrency & performance medium

How to Implement a Token Bucket Rate Limiter with asyncio in Python

This code implements a thread-safe token bucket rate limiter for asyncio, allowing you to limit the rate of async tasks or API calls.

asyncio rate-limiting token-bucket
Python
import asyncio
import time


class TokenBucket:
    def __init__(self, rate_per_second, capacity):
        self.rate = rate_per_second
        self.capacity = capacity
        self.tokens = capacity
        self.last_refill = time.monotonic()
        self.lock = asyncio.Lock()

    async def acquire(self):
        asy…
14 0 Open
Caching & Redis easy

How to implement a token bucket rate limiter in Python

A thread-safe in-memory token bucket rate limiter that tracks per-key tokens with refill logic, including a usage example after a timed refill.

rate-limiting token-bucket threading
Python
import time
import threading

class TokenBucketRateLimiter:
    def __init__(self, capacity, refill_rate):
        self.capacity = capacity
        self.refill_rate = refill_rate
        self.tokens = capacity
        self.last_refill_time = time.time()
        self.lock = threading.Lock()

    def allow_request(self,…
12 0 Open
Reliability & rate limiting easy

How to Build a Rate Limiter in Python

A beginner-friendly token bucket rate limiter with retry logic for handling API rate limits in Python.

rate-limiting token-bucket retry
Python
import time
import random

class RateLimiter:
    """Simple token bucket rate limiter for beginners."""
    
    def __init__(self, max_tokens=5, refill_rate=1.0):
        self.max_tokens = max_tokens
        self.tokens = max_tokens
        self.refill_rate = refill_rate  # tokens per second
        self.last_refill …
15 0 Open
Reliability & rate limiting medium

Leaky Bucket Rate Limiter in Python: Smooth Burst Traffic

Implements a token-bucket-style leaky bucket rate limiter that smooths bursty traffic by draining at a fixed rate and dropping excess packets.

rate-limiting traffic-shaping simulation
Python
import time
import random


class LeakyBucket:
    def __init__(self, capacity, drain_rate):
        self.capacity = capacity
        self.drain_rate = drain_rate
        self.water = 0.0
        self.last_time = time.time()

    def allow(self, packet_size=1.0):
        now = time.time()
        elapsed = now - self.…
14 0 Open
Reliability & rate limiting medium

Mock Distributed Rate Limiter with Dict in Python

Simulates a distributed token-bucket rate limiter with a thread-safe dict, useful for testing before moving to Redis.

rate-limiting token-bucket threading
Python
import time
import threading
from collections import defaultdict


class DistributedRateLimiter:
    """
    A mock distributed rate limiter using a dict with thread-safe access.
    Implements a token bucket algorithm per user.
    """

    def __init__(self, rate_per_second=5, burst_capacity=10):
        self.rate_p…
13 0 Open
Reliability & rate limiting medium

Token bucket rate limiter in Python (in-memory)

Implement a thread-safe in-memory token bucket rate limiter that throttles requests based on a steady refill rate.

rate-limiting token-bucket threading
Python
import time
import threading


class TokenBucket:
    def __init__(self, capacity, refill_rate, refill_interval=1.0):
        self.capacity = capacity
        self.tokens = capacity
        self.refill_rate = refill_rate
        self.refill_interval = refill_interval
        self.last_refill = time.monotonic()
       …
14 0 Open

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