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Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

7 matches
Data pipelines & processing medium

Deduplicate events by ID within a window in Python

Deduplicate event streams by ID within sliding time windows, keeping the newest occurrence per window using heaps and sets.

deduplication events heapq
Python
import heapq
from collections import defaultdict

def deduplicate_events(events, window_size):
    """Return events deduplicated by id, keeping newest within each sliding window."""
    # Index events by (timestamp, id) for deterministic ordering
    events_by_id = defaultdict(list)
    for ts, eid, *payload in events…
14 0 Open
Streaming & messaging medium

How to Stream Join Windowed Mock Topics in Python

Simulates two message topics and joins their events when timestamps fall within a sliding time window using Python generators and deques.

streaming join generator
Python
import itertools
import random
import time
from collections import deque
from dataclasses import dataclass, field

@dataclass
class Event:
    key: str
    value: int
    timestamp: float = field(default_factory=time.time)

def generate_topic(prefix, keys, start_time):
    while True:
        yield Event(
            …
14 0 Open
Caching & Redis medium

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.

redis rate-limit sliding-window
Python
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…
14 0 Open
Reliability & rate limiting medium

How to Implement a Sliding Window Log Rate Limiter in Python

Implements a sliding window log rate limiter in Python using a deque of timestamps to enforce a maximum request count within a rolling time window.

rate-limiting sliding-window deque
Python
from collections import deque
from datetime import datetime, timedelta
from time import sleep


class SlidingWindowLog:
    def __init__(self, window_seconds: int, max_requests: int):
        self.window_seconds = window_seconds
        self.max_requests = max_requests
        self.timestamps = deque()

    def allow_…
15 0 Open
Reliability & rate limiting medium

How to Implement a Token Bucket Rate Limiter per Client IP in Python

Implements a simple sliding-window rate limiter using a dictionary of timestamp lists per client IP to limit requests per window.

rate-limiting sliding-window ip
Python
from time import time
from collections import defaultdict

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

    def allow(self, ip: str) -> bool:
        now…
13 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
Big data & Spark medium

How to Mock and Test a Rate-Limited Source Stream in Python

Build a class that rate-limits emitted items using a sliding window and test it with a simulated stream in Python.

rate-limiting mock-testing streaming
Python
import time
from collections import deque


class RateLimitedSource:
    def __init__(self, max_rate, window=1.0):
        self.max_rate = max_rate
        self.window = window
        self._timestamps = deque()

    def emit(self, item):
        now = time.monotonic()
        while self._timestamps and self._timestam…
16 0 Open

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