Rate Limit per User ID in Python with a Dict Mock

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.time()
        timestamps = self.user_timestamps[user_id]

        while timestamps and timestamps[0] <= now - self.window_seconds:
            timestamps.pop(0)

        if len(timestamps) >= self.max_requests:
            return False

        timestamps.append(now)
        return True


if __name__ == "__main__":
    limiter = RateLimiter(max_requests=3, window_seconds=10)

    test_requests = [
        ("alice", True),
        ("alice", True),
        ("alice", True),
        ("alice", False),  # 4th request should be blocked
        ("bob", True),     # different user not affected
    ]

    for user_id, expected in test_requests:
        result = limiter.allow_request(user_id)
        print(f"user={user_id}, allowed={result}, expected={expected}")