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Python Code Samples

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

10 matches
System design patterns medium

Simulate a Leaky Bucket Rate Limiter in Python

This code implements a leaky bucket rate limiter that drains at a fixed rate and accepts or rejects incoming requests based on capacity.

rate limiting leaky bucket simulation
Python
import time
from collections import deque


class LeakyBucket:
    """Simulates a leaky bucket rate limiter with a fixed drain rate."""
    def __init__(self, capacity, drain_rate_per_sec):
        self.capacity = capacity
        self.drain_rate = drain_rate_per_sec
        self.water = 0.0
        self.last_refill =…
13 0 Open
Caching & Redis medium

Redis Leaky Bucket Rate Limiting Mock in Python

Simulates a Redis-backed leaky bucket rate limiter using a local class with continuous leaking and token capacity checks.

rate-limiting redis algorithms
Python
import time
from collections import deque


class LeakyBucket:
    def __init__(self, capacity, leak_rate):
        self.capacity = capacity
        self.leak_rate = leak_rate
        self.water = 0.0
        self.timestamp = time.time()
        self.history = deque()

    def allow(self):
        current = time.time(…
14 0 Open
Reliability & rate limiting easy

Fixed Window Counter Rate Limiting in Python

A simple fixed window counter rate limiter that allows a maximum number of requests per 60-second window, with a mock time simulation.

rate-limiting fixed-window time
Python
from collections import deque
from time import time

class FixedWindowCounter:
    def __init__(self, max_requests):
        self.max_requests = max_requests
        self.window_start = int(time())
        self.window_count = 0

    def allow_request(self):
        current_time = int(time())
        if current_time >=…
13 0 Open
Reliability & rate limiting medium

GCRA generic cell rate algorithm in Python

Mock implementation of the Generic Cell Rate Algorithm (GCRA) for traffic shaping and rate limiting.

gcra rate-limiting traffic-shaping
Python
from collections import deque
import time

class GCRA:
    def __init__(self, rate, burst):
        self.tau = burst
        self.T = rate
        self.t = 0
        self.LCT = 0

    def add_cell(self, arrival_time):
        if arrival_time <= self.t:
            return False
        arrived_early = (arrival_time - s…
14 0 Open
Reliability & rate limiting easy

How to implement rate limiting in Python

Build a simple sliding-window rate limiter in Python that enforces a max number of calls per time period and formats data with timestamps.

rate-limiting time sliding-window
Python
import time

class RateLimiter:
    def __init__(self, max_calls, period):
        self.max_calls = max_calls
        self.period = period
        self.calls = []
    
    def allow(self):
        now = time.time()
        # Remove calls older than the period window
        self.calls = [t for t in self.calls if now -…
17 0 Open
Reliability & rate limiting easy

How to implement rate limiting in Python

A beginner-friendly Python rate limiter that throttles API calls and retries parsing tasks with exponential backoff.

rate-limiting retry parsing
Python
import time
import random

class RateLimiter:
    def __init__(self, max_calls, per_seconds):
        self.max_calls = max_calls
        self.per_seconds = per_seconds
        self.timestamps = []
    
    def allow(self):
        now = time.time()
        self.timestamps = [t for t in self.timestamps if now - t < sel…
15 0 Open
Reliability & rate limiting medium

How to implement rate limiting per API key in Python

A simple sliding-window rate limiter that tracks request timestamps per API key and rejects requests exceeding the configured limit.

rate-limiting api time-window
Python
import time

API_RATE_LIMITS = {"api_key_1": 5, "api_key_2": 3}  # max requests per window
WINDOW_SECONDS = 10

class RateLimiter:
    def __init__(self, limits, window):
        self.limits = limits
        self.window = window
        self.requests = {key: [] for key in limits}

    def allow(self, api_key):
       …
13 0 Open
Reliability & rate limiting easy

Rate Limiting in Python with a Sliding Window

A beginner-friendly dataclass-based sliding window rate limiter that controls how many calls are allowed per time window.

rate-limiting sliding-window dataclass
Python
import time
from dataclasses import dataclass


@dataclass
class RateLimiter:
    max_calls: int
    window_seconds: float = 1.0

    def __post_init__(self):
        self.calls = []
        self._start = time.monotonic()

    def _update(self, now):
        self.calls = [t for t in self.calls if now - t < self.window…
12 0 Open
Reliability & rate limiting easy

Rate Limiting with Queue Rejection in Python

Simulates a load shed pattern that rejects tasks when a queue fills up.

rate-limiting queue deque
Python
from collections import deque
import time


class RateLimiter:
    def __init__(self, max_queue_size=3):
        self.queue = deque()
        self.max_queue_size = max_queue_size
        self.rejected_count = 0

    def submit(self, task_name):
        if len(self.queue) >= self.max_queue_size:
            self.reject…
15 0 Open
Reliability & rate limiting easy

Rate Limiting with a Simple Python RateLimiter Class

A beginner-friendly Python rate limiter that tracks call timestamps and enforces a maximum number of calls within a rolling time window, with a helper to validate positive integers.

rate-limiting time api
Python
import time

class RateLimiter:
    def __init__(self, max_calls, period_seconds):
        self.max_calls = max_calls
        self.period_seconds = period_seconds
        self.calls = []

    def is_allowed(self):
        now = time.time()
        while self.calls and now - self.calls[0] >= self.period_seconds:
      …
13 0 Open

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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.